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Taxon author: A. Gray

ITIS records citing taxon author "A. Gray"
 
 Kingdom Plantae
  Abronia cycloptera A. Gray -- not accepted
  Abutilon berlandieri A. Gray ex S. Watson -- accepted -- Berlandier's Indian mallow
  Abutilon hulseanum (Torr. & A. Gray) Torr. ex A. Gray -- accepted -- mauve
  Abutilon hypoleucum A. Gray -- accepted -- whiteleaf Indian mallow
  Abutilon palmeri A. Gray -- accepted -- Palmer's Indian mallow
  Abutilon parvulum A. Gray -- accepted -- dwarf abutilon, dwarf Indian mallow
  Abutilon sonorae A. Gray -- not accepted
  Abutilon texense Torr. & A. Gray -- not accepted
  Abutilon thurberi A. Gray -- not accepted -- Thurber's Indian mallow
  Abutilon wrightii A. Gray -- accepted -- Wright's abutilon, Wright's Indian mallow
  Acacia angustissima var. texensis (Torr. & A. Gray) Isely -- accepted -- prairie wattle, whiteball acacia
  Acacia greggii A. Gray -- not accepted -- catclaw, catclaw acacia, devilsclaw, Gregg's catclaw, Texas catclaw
  Acacia greggii var. greggii A. Gray -- not accepted -- Arizona acacia, catclaw, catclaw acacia, catclaw mimosa
  Acacia koa A. Gray -- accepted -- koa
  Acacia richii A. Gray -- accepted -- Tasmanian wattle
  Acacia texensis Torr. & A. Gray -- not accepted
  Acaena exigua A. Gray -- accepted -- liliwai
  Acaena exigua var. exigua A. Gray -- not accepted
  Acalypha gracilens A. Gray -- accepted -- slender copperleaf, slender threeseed mercury
  Acalypha gracilens ssp. monococca (Engelm. ex A. Gray) G.L. Webster -- not accepted
  Acalypha gracilens var. gracilens A. Gray -- not accepted -- slender threeseed mercury
  Acalypha gracilens var. monococca Engelm. ex A. Gray -- not accepted
  Acalypha monococca (Engelm. ex A. Gray) Lill. W. Mill. & Gandhi -- accepted -- slender threeseed mercury
  Acalypha virginica var. gracilens (A. Gray) Müll. Arg. -- not accepted
  Acalypha virginica var. monococca (Engelm. ex A. Gray) Müll. Arg. -- not accepted
  Acamptopappus (A. Gray) A. Gray -- accepted -- goldenhead
  Acamptopappus shockleyi A. Gray -- accepted -- Shockley's goldenhead
  Acamptopappus sphaerocephalus (Harv. & A. Gray ex A. Gray) A. Gray -- accepted -- rayless goldenhead
  Acamptopappus sphaerocephalus var. sphaerocephalus (Harv. & A. Gray ex A. Gray) A. Gray -- accepted -- rayless goldenhead
  Acanthogonum polygonoides (Torr. & A. Gray) Goodman -- not accepted
  Acanthomintha (A. Gray) A. Gray -- accepted -- thorn-mint, thornmint
  Acanthomintha ilicifolia (A. Gray) A. Gray -- accepted -- San Diego thorn-mint, San Diego thornmint
  Acer californica (Torr. & A. Gray) Wesm. -- not accepted
  Acer californicum (Torr. & A. Gray) D. Dietr. -- not accepted
  Acer glabrum var. tripartitum (Nutt. ex Torr. & A. Gray) Pax -- not accepted
  Acer negundo ssp. californicum (Torr. & A. Gray) Wesm. -- not accepted
  Acer negundo var. californicum (Torr. & A. Gray) Sarg. -- accepted -- box elder, California boxelder
  Acer rubrum var. trilobum Torr. & A. Gray ex K. Koch -- accepted -- red maple
  Acer tripartitum Nutt. ex Torr. & A. Gray -- not accepted
  Acerates viridiflora var. linearis A. Gray -- not accepted
  Achillea millefolium var. rosea (Desf.) Torr. & A. Gray -- not accepted
  Achyranthes mutica A. Gray -- accepted -- blunt chaff flower
  Achyronychia Torr. & A. Gray -- accepted
  Achyronychia cooperi Torr. & A. Gray -- accepted -- Cooper's frostmat, onyxflower
  Acleisanthes A. Gray -- accepted -- trumpets
  Acleisanthes anisophylla A. Gray -- accepted -- obliqueleaf trumpets
  Acleisanthes berlandieri A. Gray -- not accepted
  Acleisanthes chenopodioides (A. Gray) R.A. Levin -- accepted -- goosefoot moonpod
  Acleisanthes crassifolia A. Gray -- accepted -- Texas trumpets
  Acleisanthes diffusa (A. Gray) R.A. Levin -- accepted -- spreading moonpod
  Acleisanthes longiflora A. Gray -- accepted -- angel trumpet, angel's trumpets
  Acleisanthes wrightii (A. Gray) Benth. & Hook. f. ex Hemsl. -- accepted -- Wright's trumpets
  Acmispon argophyllus (A. Gray) Brouillet -- accepted -- silver bird's-foot trefoil
  Acmispon argophyllus var. argophyllus (A. Gray) Brouillet -- accepted -- silver bird's-foot trefoil
  Acmispon argophyllus var. fremontii (A. Gray) Brouillet -- accepted -- Fremont's birdsfoot trefoil
  Acmispon heermannii var. orbicularis (A. Gray) Brouillet -- accepted -- Heermann's bird's-foot trefoil
  Acmispon wrightii (A. Gray) Brouillet -- accepted -- Wright's deervetch
  Acnida australis A. Gray -- not accepted
  Aconitum noveboracense A. Gray ex Coville -- not accepted -- northern blue monkshood, northern wild monkshood
  Aconitum reclinatum A. Gray -- accepted -- trailing white monkshood
  Aconitum uncinatum ssp. noveboracense (A. Gray ex Coville) Hardin -- not accepted
  Aconogonon davisiae (W.H. Brewer ex A. Gray) Soják -- accepted -- Davis' knotweed
  Aconogonon davisiae var. davisiae (W.H. Brewer ex A. Gray) Soják -- accepted -- Davis' knotweed
  Aconogonum davisiae (W.H. Brewer ex A. Gray) Soják -- not accepted
  Acourtia nana (A. Gray) Reveal & King -- accepted -- desert holly, dwarf desertpeony
  Acourtia thurberi (A. Gray) Reveal & King -- accepted -- Thurber's desertpeony
  Acourtia wrightii (A. Gray) Reveal & King -- accepted -- brownfoot, pink perezzia, Wright's desertpeony
  Acronychia heterophylla A. Gray -- accepted
  Actaea racemosa var. dissecta (A. Gray) J. Compton -- not accepted
  Actinea cooperi (A. Gray) Kuntze -- not accepted
  Actinea grandiflora (Torr. & A. Gray ex A. Gray) Kuntze -- not accepted
  Actinea vaseyi (A. Gray) Kuntze -- not accepted
  Actinella argentea A. Gray -- not accepted
  Actinella richardsonii var. floribunda A. Gray -- not accepted
  Actinomeris longifolia A. Gray -- not accepted
  Actinospermum angustifolium (Pursh) Torr. & A. Gray -- not accepted
  Acuan leptolobum (Torr. & A. Gray) Kuntze -- not accepted
  Adenophyllum cooperi (A. Gray) Strother -- accepted -- Cooper's dogweed, Cooper's dyssodia
  Adenophyllum porophylloides (A. Gray) Strother -- accepted -- San Felipe dogweed, San Felipe dyssodia
  Adenophyllum wrightii A. Gray -- accepted -- Wright's dogweed
  Aesculus pavia var. discolor (Pursh) A. Gray -- not accepted
  Agalinis paupercula (A. Gray) Britton -- not accepted -- smallflower false foxglove
  Agalinis paupercula var. paupercula (A. Gray) Britton -- not accepted -- smallflower false foxglove
  Agassizia suavis A. Gray & Engelm. -- not accepted
  Agastache breviflora (A. Gray) Epling -- accepted -- Trans-Pecos giant hyssop
  Agastache breviflora var. havardii (A. Gray) Shinners -- not accepted
  Agastache micrantha (A. Gray) Wooton & Standl. -- accepted -- white giant hyssop
  Agastache pallidiflora ssp. havardii (A. Gray) Lint & Epling -- not accepted
  Agastache pallidiflora ssp. neomexicana var. havardii (A. Gray) R.W. Sanders -- not accepted -- Bill Williams Mountain giant hyssop, Havard's giant hyssop
  Agastache pallidiflora var. havardii (A. Gray) R.W. Sanders -- accepted -- Bill Williams Mountain giant hyssop
  Ageratina altissima var. angustata (A. Gray) Clewell & Woot. -- not accepted -- white snakeroot
  Ageratina aromatica var. incisa (A. Gray) C.F. Reed -- not accepted -- lesser snakeroot
  Ageratina herbacea (A. Gray) King & H. Rob. -- accepted -- fragrant snakeroot, herbaceous joepyeweed
  Ageratina paupercula (A. Gray) King & H. Rob. -- accepted -- Santa Rita snakeroot
  Ageratina rothrockii (A. Gray) King & H. Rob. -- accepted -- Rothrock's snakeroot
  Ageratina wrightii (A. Gray) King & H. Rob. -- accepted -- Wright's snakeroot
  Ageratum littorale A. Gray -- not accepted -- Cape Sable whiteweed
  Agnorhiza bolanderi (A. Gray) W.A. Weber -- accepted -- Bolander's mule-ears
  Agnorhiza ovata (Torr. & A. Gray ex Torr.) W.A. Weber -- accepted -- southern mule-ears
  Agoseris alpestris (A. Gray) Greene -- not accepted
  Agoseris aurantiaca ssp. purpurea (A. Gray) G.W. Douglas -- not accepted
  Agoseris aurantiaca var. purpurea (A. Gray) Cronquist -- accepted -- orange agoseris, pale agoseris
  Agoseris barbellulata (Greene ex A. Gray) Greene -- not accepted
  Agoseris glauca var. dasycephala (Torr. & A. Gray) Jeps. -- accepted -- pale agoseris, pale goat-chicory
  Agrimonia eupatoria var. mollis Torr. & A. Gray -- not accepted
  Agrimonia incisa Torr. & A. Gray -- accepted -- incised agrimony, incised groovebur
  Agrimonia mollis (Torr. & A. Gray) Britton -- not accepted
  Agrostis alba var. aristata A. Gray -- not accepted
  Agrostis alopecuroides (Buckley) A. Gray -- not accepted
  Agrostis barbata Buckley ex A. Gray -- not accepted
  Agrostis heterolepis (A. Gray) Alph. Wood -- not accepted
  Agrostis michauxii var. laxiflora (Michaux) A. Gray -- not accepted
  Agrostis oregonensis Nutt. ex A. Gray -- not accepted
  Agrostis scabrata Nutt. ex A. Gray -- not accepted
  Agrostis vulgaris var. aristata A. Gray -- not accepted
  Aira caespitosa var. arctica (Spreng.) Thurb. ex A. Gray -- not accepted
  Aldenella tenuifolia (Torr. & A. Gray) Greene -- not accepted
  Alectoroctonum wrightii (Torr. & A. Gray) Klotzsch & Garcke -- not accepted
  Aletes anisatus (A. Gray) W.L. Theob. & C.C. Tseng -- accepted -- Rocky Mountain Indian parsley
  Aletes nuttallii (A. Gray) W.A. Weber -- not accepted
  Aletes tenuifolius (Nutt. ex Torr. & A. Gray) W.A. Weber -- not accepted
  Aliciella caespitosa (A. Gray) J.M. Porter -- accepted -- Rabbit Valley gilia, wonderland Alice-flower
  Aliciella cespitosa (A. Gray) J.M. Porter -- not accepted -- wonderland Alice-flower
  Aliciella haydenii (A. Gray) J.M. Porter -- accepted -- San Juan gilia
  Aliciella leptomeria (A. Gray) J.M. Porter -- accepted -- sand gilia
  Aliciella micromeria (A. Gray) J.M. Porter -- accepted -- dainty gilia
  Aliciella pinnatifida (Nutt. ex A. Gray) J.M. Porter -- accepted -- sticky gilia
  Aliciella stenothyrsa (A. Gray) J.M. Porter -- accepted -- Uinta Basin gilia
  Aliciella subnuda (Torr. ex A. Gray) J.M. Porter -- accepted -- coral gilia
  Alisma lanceolatum A. Gray -- not accepted -- lanceleaf water plantain
  Allioniella oxybaphoides (A. Gray) Rydb. -- not accepted
  Allium occidentale A. Gray -- not accepted
  Allocarya glaber (A. Gray) J.F. Macbr. -- not accepted
  Allocarya greenei (A. Gray) Greene -- not accepted
  Allocarya lithocarya Greene ex A. Gray -- not accepted
  Allocarya mollis (A. Gray) Greene -- not accepted
  Allocarya trachycarpa (A. Gray) Greene -- not accepted
  Allotropa Torr. & A. Gray ex A. Gray -- accepted -- sugar stick, sugarstick
  Allotropa virgata Torr. & A. Gray ex A. Gray -- accepted -- sugarstick
  Aloysia wrightii (A. Gray) A. Heller -- accepted -- lemon verbena, mintbush lippia, Wright's aloysia, Wright's beebrush, Wright's lippia
  Alyxia oliviformis var. myrtillifolia A. Gray ex Hillebr. -- not accepted
  Amaranthus australis (A. Gray) J.D. Sauer -- accepted -- southern amaranth
  Amaranthus obcordatus (A. Gray) Standl. -- accepted -- Trans-Pecos amaranth
  Amaranthus torreyi (A. Gray) Benth. ex S. Watson -- accepted -- Torrey's amaranthus
  Amaranthus torreyi auct. non (A. Gray) Benth. ex S. Watson -- not accepted
  Amaranthus torreyi auct. non (A. Gray) Benth. ex S. Watson -- not accepted
  Amauria dissecta A. Gray -- not accepted
  Amauriopsis dissecta (A. Gray) Rydb. -- accepted -- ragleaf bahia
  Ambrosia canescens A. Gray -- accepted -- hairy ragweed
  Ambrosia cheiranthifolia A. Gray -- accepted -- Rio Grande ragweed, South Texas ambrosia
  Ambrosia cordifolia (A. Gray) Payne -- accepted -- heartleaf bursage, Tucson bur ragweed, Tucson burr ragweed
  Ambrosia coronopifolia Torr. & A. Gray -- not accepted
  Ambrosia dumosa (A. Gray) Payne -- accepted -- burrobush, white bursage
  Ambrosia eriocentra (A. Gray) Payne -- accepted -- hollyleaf bursage, woolly bursage, woolly fruit bur ragweed, woolly fruit burr ragweed, wooly bursage
  Ambrosia ilicifolia (A. Gray) Payne -- accepted -- hollyleaf bur ragweed, hollyleaf burr ragweed, hollyleaf bursage
  Ambrosia monogyra (Torr. & A. Gray) Strother & B.G. Baldw. -- accepted -- singlewhorl burrobrush
  Ambrosia psilostachya var. coronopifolia (Torr. & A. Gray) Farw. -- not accepted
  Ambrosia pumila (Nutt.) A. Gray -- accepted -- dwarf bur ragweed, dwarf burr ragweed, San Diego ambrosia, San Diego ragweed
  Ambrosia salsola (Torr. & A. Gray) Strother & B.G. Baldw. -- accepted -- burrobrush
  Ambrosia salsola var. salsola (Torr. & A. Gray) Strother & B.G. Baldw. -- not accepted
  Ambrosia trifida var. integrifolia (Muhl. ex Willd.) Torr. & A. Gray -- not accepted
  Amelanchier alnifolia var. pumila (Torr. & A. Gray) C.K. Schneid. -- accepted -- dwarf serviceberry
  Amelanchier canadensis var. pumila Torr. & A. Gray -- not accepted -- Canadian serviceberry
  Amelanchier oblongifolia (Torr. & A. Gray) M. Roem. -- not accepted
  Amelanchier pumila (Torr. & A. Gray) Nutt. ex M. Roem. -- not accepted -- dwarf serviceberry
  Amianthium A. Gray -- accepted -- amianthium
  Amianthium muscaetoxicum (Walter) A. Gray -- not accepted -- flypoison
  Amianthium muscitoxicum (Walter) A. Gray -- accepted -- flypoison
  Ammobroma Torr. ex A. Gray -- not accepted
  Ammobroma sonorae Torr. ex A. Gray -- not accepted
  Ammocodon chenopodioides (A. Gray) Standl. -- not accepted -- goosefoot moonpod
  Ammoselinum Torr. & A. Gray -- accepted -- sandparsley
  Ammoselinum popei Torr. & A. Gray -- accepted -- plains sandparsley
  Amoreuxia wrightii A. Gray -- accepted -- Wright's yellowshow
  Amorpha paniculata Torr. & A. Gray -- accepted -- panicled false indigo, panicled indigobush
  Amphicarpaea pitcheri Torr. & A. Gray -- not accepted
  Amphipappus Torr. & A. Gray -- accepted -- amphipappus, chaffbush
  Amphipappus fremontii Torr. & A. Gray ex A. Gray -- accepted -- chaffbush, Fremont's chaffbush
  Amphipappus fremontii ssp. fremontii Torr. & A. Gray ex A. Gray -- not accepted -- Fremont's chaffbush
  Amphipappus fremontii var. fremontii Torr. & A. Gray ex A. Gray -- accepted -- chaff-bush, Fremont's chaffbush
  Amsinckia echinata A. Gray -- not accepted
  Amsinckia grandiflora (Kleeb. ex A. Gray) Kleeb. ex Greene -- accepted -- large-flowered fiddleneck, largeflowered fiddleneck
  Amsinckia intermedia var. echinata (A. Gray) Wiggins -- not accepted
  Amsinckia spectabilis var. bracteosa (A. Gray) B. Boivin -- not accepted
  Amsinckia tessellata A. Gray -- accepted -- bristly fiddleneck, western fiddleneck
  Amsinckia tessellata var. tessellata A. Gray -- accepted -- bristly fiddleneck
  Amsonia brevifolia A. Gray -- not accepted
  Amsonia ciliata var. texana (A. Gray) J.M. Coult. -- accepted -- Texas bluestar
  Amsonia palmeri A. Gray -- accepted -- Palmer's bluestar
  Anaphalis margaritacea var. subalpina A. Gray -- not accepted
  Ancistrocarphus A. Gray -- accepted -- neststraw, woolly fishhooks
  Ancistrocarphus filagineus A. Gray -- accepted -- false neststraw, hooded neststraw
  Androsace arizonica A. Gray -- not accepted
  Androsace laevigata (A. Gray) Wendelbo -- accepted -- cliff dwarf-primrose
  Androsace montana (A. Gray) Wendelbo -- accepted -- Rocky Mountain dwarf-primrose
  Androsace occidentalis var. arizonica (A. Gray) H. St. John -- not accepted
  Androsace septentrionalis ssp. subulifera (A. Gray) G.T. Robbins -- not accepted -- pygmyflower rockjasmine
  Androsace septentrionalis var. subulifera A. Gray -- not accepted
  Anelsonia eurycarpa (A. Gray) J.F. Macbr. & Payson -- accepted -- broad pod anelsonia, daggerpod
  Anemone cylindrica A. Gray -- accepted -- candle anemone, cottonweed
  Anemone decapetala var. heterophylla (Torr. & A. Gray) Britton & Rusby -- not accepted
  Anemone globosa (Torr. & A. Gray) Nutt. ex Pritz. -- not accepted
  Anemone heterophylla Nutt. ex Torr. & A. Gray (pro. syn.) -- not accepted
  Anemone heterophyllum Nutt. ex Torr. & A. Gray (pro. syn.) -- not accepted
  Anemone multifida ssp. globosa (Torr. & A. Gray) Torr. & A. Gray -- not accepted
  Anemone multifida var. globosa Torr. & A. Gray -- not accepted
  Anemone oregana A. Gray -- accepted -- blue windflower
  Anemone oregana var. oregana A. Gray -- accepted -- blue windflower
  Anemone patens var. nuttalliana (DC.) A. Gray -- not accepted
  Anemone quinquefolia var. oregana (A. Gray) B.L. Rob. -- not accepted
  Angelica arguta Nutt. ex Torr. & A. Gray -- accepted -- angelica, Lyall's angelica, sharptooth angelica
  Angelica arguta var. breweri (A. Gray) Di Tomaso -- not accepted
  Angelica breweri A. Gray -- accepted -- Brewer's angelica
  Angelica lineariloba A. Gray -- accepted -- poison angelica, Sierra angelica
  Anisacanthus insignis A. Gray -- not accepted
  Anisacanthus thurberi (Torr.) A. Gray -- accepted -- desert honeysuckle, Thurber's desert honeysuckle
  Anisacanthus wrightii (Torr.) A. Gray -- not accepted
  Anisocoma Torr. & A. Gray -- accepted -- anisocoma
  Anisocoma acaulis Torr. & A. Gray -- accepted -- scale bud, scalebud
  Anisophyllum fendleri (Torr. & A. Gray) Klotzsch & Garcke -- not accepted
  Anisophyllum humistratum (Engelm. ex A. Gray) Klotzsch & Garcke -- not accepted
  Anisophyllum melanadenium (Torr. & A. Gray) Klotzsch & Garcke -- not accepted
  Anoda abutiloides A. Gray -- accepted -- Indian anoda
  Anoda cristata var. digitata (A. Gray) Hochr. -- not accepted
  Anoda pentaschista A. Gray -- accepted -- field anoda
  Anoda thurberi A. Gray -- accepted -- Arizona anoda
  Anoda wrightii A. Gray -- not accepted
  Anogra coronopifolia (Torr. & A. Gray) Britton -- not accepted
  Antennaria alpina var. stenophylla A. Gray -- not accepted
  Antennaria dimorpha (Nutt.) Torr. & A. Gray -- accepted -- low everlasting, low pussytoes
  Antennaria dimorpha var. flagellaris A. Gray -- not accepted
  Antennaria flagellaris (A. Gray) A. Gray -- accepted -- stoloniferous pussy-toes, whip pussytoes
  Antennaria geyeri A. Gray -- accepted -- Geyer's everlasting, mountain pussytoes, pinewoods pussytoes
  Antennaria luzuloides Torr. & A. Gray -- accepted -- rush pussytoes
  Antennaria luzuloides ssp. luzuloides Torr. & A. Gray -- accepted -- rush pussytoes
  Antennaria luzuloides var. argentea (Benth.) A. Gray -- not accepted
  Antennaria luzuloides var. microcephala (A. Gray) Cronquist -- not accepted
  Antennaria microcephala A. Gray -- not accepted
  Antennaria monocephala (Torr. & A. Gray) Greene non Antennaria monocephala DC. -- not accepted
  Antennaria plantaginifolia var. monocephala Torr. & A. Gray -- not accepted
  Antennaria stenophylla (A. Gray) A. Gray -- accepted -- narrowleaf everlasting, narrowleaf pussytoes
  Antheropeas lanosum (A. Gray) Rydb. -- not accepted -- white easter-bonnets, white easterbonnets
  Antheropeas wallacei (A. Gray) Rydb. -- not accepted -- Wallace's woolydaisy, woolly easter-bonnets, woolly easterbonnets
  Anticlea occidentalis (A. Gray) Zomlefer & Judd -- accepted -- western featherbells
  Antiphytum floribundum (Torr.) A. Gray -- accepted -- Texas saucerflower
  Antirrhinum breweri A. Gray -- not accepted
  Antirrhinum cooperi A. Gray -- not accepted
  Antirrhinum cornutum var. leptaleum (A. Gray) Munz -- not accepted
  Antirrhinum coulterianum ssp. orcuttianum (A. Gray) Pennell -- not accepted
  Antirrhinum filipes A. Gray -- not accepted
  Antirrhinum leptaleum A. Gray -- not accepted
  Antirrhinum maurandioides A. Gray -- not accepted
  Antirrhinum nuttallianum ssp. subsessile (A. Gray) D.M. Thomps. -- not accepted
  Antirrhinum subcordatum A. Gray -- not accepted -- dimorphic snapdragon
  Antirrhinum subsessile A. Gray -- not accepted
  Antirrhinum vexillocalyculatum ssp. breweri (A. Gray) D.M. Thomps. -- not accepted
  Antirrhinum virga A. Gray -- not accepted
  Antirrhinum wislizeni (Engelm. ex A. Gray) Tidestr. -- not accepted
  Anulocaulis eriosolenus (A. Gray) Standl. -- accepted -- Big Bend ringstem
  Anychiastrum baldwinii (Torr. & A. Gray) Small -- not accepted
  Apargidium Torr. & A. Gray -- not accepted
  Apargidium boreale (Bong.) Torr. & A. Gray -- not accepted
  Aphanostephus arizonicus A. Gray -- not accepted
  Aphanostephus humilis (Benth.) A. Gray -- not accepted
  Aphanostephus riddellii Torr. & A. Gray -- accepted -- Riddell's dozedaisy
  Aphantochaeta exilis A. Gray -- not accepted
  Aphyllon cooperi A. Gray -- not accepted
  Aphyllon fasciculatum (Nutt.) Torr. & A. Gray -- not accepted
  Aphyllon pinorum (Geyer ex Hook.) A. Gray -- not accepted
  Aphyllon tuberosum (A. Gray) A. Gray -- not accepted
  Aphyllon uniflorum (L.) A. Gray -- not accepted
  Apiastrum Nutt. ex Torr. & A. Gray -- accepted
  Aplopappus sphaerocephalus Harv. & A. Gray ex A. Gray -- not accepted
  Aplopappus tortifolius Torr. & A. Gray -- not accepted
  Apocynum album var. hypericifolium A. Gray -- not accepted
  Apocynum androsaemifolium ssp. pumilum (A. Gray) B. Boivin -- not accepted -- spreading dogbane
  Apocynum androsaemifolium ssp. pumilum var. pumilum A. Gray -- not accepted -- low dogbane
  Apocynum androsaemifolium var. pumilum A. Gray -- not accepted
  Apocynum cannabinum var. hypericifolium (Aiton) A. Gray -- not accepted
  Apocynum pumilum (A. Gray) Greene -- not accepted
  Apodanthera undulata A. Gray -- accepted -- melon loco, melon-loco
  Aquilegia chrysantha A. Gray -- accepted -- golden columbine
  Aquilegia chrysantha var. chrysantha A. Gray -- not accepted -- golden columbine
  Aquilegia longissima A. Gray ex S. Watson -- accepted -- long spur columbine, longspur columbine
  Arabis arcuata (Nutt.) A. Gray -- not accepted
  Arabis brachycarpa (Torr. & A. Gray) Britton -- not accepted
  Arabis dentata (Torr.) Torr. & A. Gray -- not accepted
  Arabis drummondii A. Gray -- not accepted -- Canadian rockcress, Drummond rockcress, Drummond's rockcress
  Arabis hirsuta var. glabrata Torr. & A. Gray -- not accepted -- mountain rockcress
  Arabis petiolaris (A. Gray) A. Gray -- not accepted -- Brazos rockcress
  Arabis platysperma A. Gray -- not accepted -- pioneer rockcress
  Arabis platysperma var. platysperma A. Gray -- not accepted -- pioneer rockcress
  Aragallus oreophilus (A. Gray) A. Nelson -- not accepted
  Arbutus arizonica (A. Gray) Sarg. -- accepted -- Arizona madrone
  Arbutus xalapensis var. arizonica A. Gray -- not accepted
  Arbutus xalapensis var. texana (Buckley) A. Gray -- not accepted
  Arctostaphylos andersonii A. Gray -- accepted -- Santa Cruz manzanita
  Arctostaphylos bicolor (Nutt.) A. Gray -- not accepted
  Arctostaphylos diversifolia (Parry) Parry ex A. Gray -- not accepted
  Arctostaphylos nevadensis A. Gray -- accepted -- pinemat manzanita
  Arctostaphylos nevadensis ssp. nevadensis A. Gray -- accepted -- pine-mat manzanita, pinemat manzanita
  Arctostaphylos nummularia A. Gray -- not accepted
  Arctostaphylos nummularia A. Gray -- accepted -- glossyleaf manzanita
  Arctostaphylos nummularia ssp. nummularia A. Gray -- accepted -- glossyleaf manzanita
  Arctostaphylos patula ssp. platyphylla (A. Gray) P.V. Wells -- not accepted
  Arctostaphylos pungens ssp. nevadensis (A. Gray) Roof -- not accepted
  Arctous (A. Gray) Nied. -- accepted -- bearberry
  Arcytophyllum fasciculatum (A. Gray) Terrell & H. Rob. -- accepted
  Arenaria benthamii Fenzl ex Torr. & A. Gray -- accepted -- hilly sandwort
  Arenaria brevifolia Nutt. ex Torr. & A. Gray -- not accepted
  Arenaria californica (A. Gray) W.H. Brewer -- not accepted
  Arenaria congesta var. suffrutescens (A. Gray) B.L. Rob. -- not accepted -- suffrutescent sandwort
  Arenaria douglasii Fenzl ex Torr. & A. Gray -- not accepted
  Arenaria fendleri A. Gray -- not accepted -- Fendler's sandwort
  Arenaria fendleri var. fendleri A. Gray -- not accepted -- Fendler's sandwort
  Arenaria lanuginosa ssp. saxosa (A. Gray) Maguire -- not accepted -- spreading sandwort
  Arenaria lanuginosa var. saxosa (A. Gray) Zarucchi, R.L. Hartm. & Rabeler -- accepted -- spreading sandwort
  Arenaria saxosa A. Gray -- not accepted
  Argemone hispida A. Gray -- accepted -- rough prickly poppy, rough pricklypoppy
  Argemone platyceras var. hispida (A. Gray) Prain -- not accepted
  Argyroxiphium macrocephalum A. Gray -- not accepted
  Argyroxiphium sandwicense ssp. macrocephalum (A. Gray) Mérat -- accepted -- `ahinahina, Haleakala silversword, Hawai'i silversword
  Argythammia humilis (Engelm. & A. Gray) Müll. Arg. -- not accepted
  Argythamnia adenophora A. Gray -- not accepted -- glandular silverbush
  Argythamnia adenophora auct. non A. Gray -- not accepted
  Argythamnia humilis (Engelm. & A. Gray) Müll. Arg. -- not accepted -- low silverbush, low wildmercury
  Argythamnia humilis var. humilis (Engelm. & A. Gray) Müll. Arg. -- not accepted -- low silverbush, low wildmercury
  Arida blepharophylla (A. Gray) D.R. Morgan & R.L. Hartm. -- accepted -- gypsum tansy-aster
  Arida carnosa (A. Gray) D.R. Morgan & R.L. Hartm. -- accepted -- shrubby alkali tansy-aster, shrubby alkaliaster
  Arida parviflora (A. Gray) D.R. Morgan & R.L. Hartm. -- accepted -- small-flower tansy-aster
  Aristida basiramea var. curtissii (A. Gray) Shinners -- not accepted
  Aristida curtissii (A. Gray) Nash -- not accepted
  Aristida dichotoma var. curtissii A. Gray -- accepted -- Curtis' threeawn
  Aristida gracilis var. depauperata A. Gray -- not accepted
  Aristida ramosissima Engelm. ex A. Gray -- accepted -- s curve threeawn, s-curve threeawn
  Aristida ramosissima f. uniaristata (A. Gray) Mohlenbr. -- not accepted
  Aristida ramosissima var. ramosissima Engelm. ex A. Gray -- accepted -- s-curve threeawn
  Aristida ramosissima var. uniaristata A. Gray -- not accepted
  Aristolochia longiflora Engelm. & A. Gray -- not accepted
  Armoracia lacustris (A. Gray) Al-Shehbaz & V.M. Bates -- not accepted -- armoracie des étangs, lake-cress
  Arnica chamissonis ssp. foliosa var. incana (A. Gray) Hultén -- not accepted -- Chamisso arnica, hoary arnica
  Arnica chamissonis ssp. incana (A. Gray) Maguire -- not accepted
  Arnica dealbata (A. Gray) B.G. Baldw. -- accepted -- mock leopardbane
  Arnica discoidea var. eradiata (A. Gray) Cronquist -- not accepted
  Arnica foliosa var. incana A. Gray -- not accepted
  Arnica nevadensis A. Gray -- accepted -- Nevada arnica
  Arnica parryi A. Gray -- accepted -- nodding arnica, Parry's arnica, Sonne's arnica
  Arnica parryi ssp. parryi A. Gray -- not accepted -- Parry's arnica
  Arnica parviflora A. Gray -- not accepted
  Arnica viscosa A. Gray -- accepted -- Mt. Shasta arnica
  Arnoglossum diversifolium (Torr. & A. Gray) H. Rob. -- accepted -- variableleaf Indian plaintain, variableleaf Indian plantain
  Arnoglossum floridanum (A. Gray) H. Rob. -- accepted -- Florida cacalia
  Artemisia bigelovii A. Gray -- accepted -- Bigelow sage, Bigelow sagebrush, Bigelow's sagebrush
  Artemisia bolanderi A. Gray -- not accepted
  Artemisia cana ssp. bolanderi (A. Gray) G.H. Ward -- accepted -- Bolander's silver sagebrush, silver sagebrush
  Artemisia carruthii var. wrightii (A. Gray) S.F. Blake -- not accepted
  Artemisia elatior (Torr. & A. Gray) Rydb. -- not accepted
  Artemisia laciniata ssp. parryi (A. Gray) W.A. Weber -- accepted -- Parry's wormwood
  Artemisia ludoviciana ssp. redolens (A. Gray) D.D. Keck -- accepted -- white sagebrush, white sagewort
  Artemisia ludoviciana var. gnaphalodes (Nutt.) Torr. & A. Gray -- not accepted
  Artemisia ludoviciana var. latifolia (Besser) Torr. & A. Gray -- not accepted
  Artemisia ludoviciana var. mexicana (Willd. ex Spreng.) A. Gray -- not accepted
  Artemisia ludoviciana var. redolens (A. Gray) Shinners -- not accepted
  Artemisia mauiensis (A. Gray) Skottsb. -- accepted -- Maui wormwood
  Artemisia palmeri A. Gray -- accepted -- San Diego sagewort
  Artemisia parryi A. Gray -- not accepted -- Parry's wormwood
  Artemisia pattersonii A. Gray -- accepted -- Patterson's wormwood
  Artemisia pygmaea A. Gray -- accepted -- pygmy sagebrush
  Artemisia redolens A. Gray -- not accepted
  Artemisia rigida (Nutt.) A. Gray -- accepted -- scabland sagebrush
  Artemisia rothrockii A. Gray -- accepted -- timberline sagebrush
  Artemisia scopulorum A. Gray -- accepted -- alpine sagebrush, dwarf sagebrush
  Artemisia tilesii ssp. elatior (Torr. & A. Gray) Hultén -- not accepted -- Tilesius' wormwood
  Artemisia tilesii var. elatior Torr. & A. Gray -- not accepted
  Artemisia tridentata ssp. bolanderi (A. Gray) H.M. Hall & Clem. -- not accepted
  Artemisia tridentata ssp. parishii (A. Gray) H.M. Hall & Clem. -- accepted -- big sagebrush
  Artemisia tridentata ssp. rothrockii (A. Gray) H.M. Hall & Clem. -- not accepted
  Artemisia tridentata var. angustifolia A. Gray -- not accepted
  Artemisia tridentata var. bolanderi (A. Gray) McMinn -- not accepted
  Artemisia tridentata var. parishii (A. Gray) Jeps. -- not accepted
  Artemisia tridentata var. rothrockii (A. Gray) McMinn -- not accepted
  Artemisia vulgaris var. mexicana (Willd. ex Spreng.) Torr. & A. Gray -- not accepted
  Asanthus squamulosus (A. Gray) King & H. Rob. -- accepted -- Mule Mountain brickellbush
  Asarina filipes (A. Gray) Pennell -- not accepted
  Asarina wislizeni (Engelm. ex A. Gray) Pennell -- not accepted
  Asclepias curtissii A. Gray -- accepted -- Curtiss' milkweed
  Asclepias feayi Chapm. ex A. Gray -- accepted -- Feay's milkweed, Florida milkweed
  Asclepias hallii A. Gray -- accepted -- Hall's milkweed
  Asclepias hypoleuca (A. Gray) Woodson -- accepted -- mahogany milkweed, talayote
  Asclepias lemmonii A. Gray -- accepted -- big-leaf milkweed, bigleaf milkweed, Lemmon's milkweed
  Asclepias meadii Torr. ex A. Gray -- accepted -- Mead's milkweed
  Asclepias nyctaginifolia A. Gray -- accepted -- Mojave milkweed
  Asclepias pumila (A. Gray) Vail -- accepted -- low milkweed, plains milkweed
  Asclepias quinquedentata A. Gray -- accepted -- slim-pod milkweed, slimpod milkweed
  Asclepias stenophylla A. Gray -- accepted -- slimleaf milkweed
  Asclepias subverticillata (A. Gray) Vail -- accepted -- horsetail milkweed, poison milkweed, western whorled milkweed, whorled milkweed
  Asclepias sullivantii Engelm. ex A. Gray -- accepted -- prairie milkweed, Sullivant's milkweed
  Asclepias viridiflora var. linearis (A. Gray) Fernald -- not accepted
  Asclepiodella feayi (Chapm. ex A. Gray) Small -- not accepted
  Asclepiodora decumbens (Nutt.) A. Gray -- not accepted
  Asclepiodora viridis (Walter) A. Gray -- not accepted
  Aspicarpa hyssopifolia A. Gray -- accepted -- hyssopleaf asphead
  Aspicarpa longipes A. Gray -- accepted -- spreading asphead
  Aster alpigenus (Torr. & A. Gray) A. Gray -- not accepted
  Aster alpigenus ssp. andersonii (A. Gray) Onno -- not accepted
  Aster alpigenus var. andersonii (A. Gray) Onno ex M. Peck -- not accepted
  Aster andersonii (A. Gray) A. Gray -- not accepted
  Aster anomalus Engelm. ex Torr. & A. Gray -- not accepted -- manyray aster
  Aster apricus (A. Gray) Rydb. -- not accepted
  Aster ascendens var. fremontii Torr. & A. Gray -- not accepted
  Aster ascendens var. yosemitanus A. Gray -- not accepted
  Aster baldwinii Torr. & A. Gray. -- not accepted
  Aster bigelovii A. Gray -- not accepted
  Aster blepharophyllus A. Gray -- not accepted
  Aster bloomeri A. Gray -- not accepted
  Aster borealis (Torr. & A. Gray) Prov. -- not accepted -- rush aster
  Aster breweri (A. Gray) Semple -- not accepted
  Aster campestris var. bloomeri (A. Gray) A. Gray -- not accepted -- Bloomer's aster
  Aster canescens var. latifolius (A. Gray) A. Gray -- not accepted
  Aster canescens var. viscosus (Nutt.) A. Gray -- not accepted
  Aster chapmanii Torr. & A. Gray -- not accepted -- savannah aster
  Aster chilensis ssp. hallii (A. Gray) Cronquist -- not accepted
  Aster coloradoensis A. Gray -- not accepted
  Aster commutatus (Torr. & A. Gray) A. Gray -- not accepted
  Aster curtisii Torr. & A. Gray -- not accepted
  Aster cusickii A. Gray -- not accepted -- Cusick's aster
  Aster cusickii var. lyallii A. Gray -- not accepted
  Aster diffusus var. thyrsoides A. Gray -- not accepted
  Aster divaricatus (Nutt.) Torr. & A. Gray non L. -- not accepted -- aster ŕ rameaux étalés, serpentine aster, white wood aster
  Aster divaricatus var. sandwicensis A. Gray -- not accepted
  Aster dumosus var. cordidifolius (Michx.) Torr. & A. Gray -- not accepted
  Aster dumosus var. coridifolius (Michx.) Torr. & A. Gray -- not accepted
  Aster dumosus var. gracilentus Torr. & A. Gray -- not accepted
  Aster dumosus var. strictior Torr. & A. Gray -- not accepted -- rice button aster
  Aster dumosus var. subulifolius Torr. & A. Gray -- not accepted -- rice button aster
  Aster eatonii (A. Gray) Howell -- not accepted -- Eaton's aster
  Aster elegans (Nutt.) Torr. & A. Gray non Willd. -- not accepted
  Aster elliotti Torr. & A. Gray -- not accepted
  Aster elliottii Torr. & A. Gray -- not accepted
  Aster elodes Torr. & A. Gray -- not accepted
  Aster engelmannii (D.C. Eaton) A. Gray -- not accepted
  Aster engelmannii var. glaucescens A. Gray -- not accepted
  Aster engelmannii var. ledophyllus A. Gray -- not accepted
  Aster ericoides var. commutatus (Torr. & A. Gray) B. Boivin -- not accepted
  Aster ericoides var. commutatus (Torr. & A. Gray) B. Boivin -- not accepted
  Aster ericoides var. platyphyllus Torr. & A. Gray -- not accepted
  Aster ericoides var. pringlei A. Gray -- not accepted
  Aster ericoides var. pusillus A. Gray -- not accepted
  Aster ericoides var. stricticaulis (Torr. & A. Gray) F.C. Gates -- not accepted -- white heath aster
  Aster ericoides var. villosus (Michx.) Torr. & A. Gray -- not accepted
  Aster eryngiifolius Torr. & A. Gray -- not accepted -- thistleleaf aster
  Aster exilis var. australis A. Gray -- not accepted
  Aster falcatus ssp. commutatus (Torr. & A. Gray) A.G. Jones -- not accepted
  Aster falcatus var. commutatus (Torr. & A. Gray) A.G. Jones -- not accepted -- cluster aster
  Aster fendleri A. Gray -- not accepted -- Fendler's aster
  Aster foliaceus var. apricus A. Gray -- not accepted -- leafybract aster
  Aster foliaceus var. burkei A. Gray -- not accepted
  Aster foliaceus var. canbyi A. Gray -- not accepted -- Canby's aster
  Aster foliaceus var. cusickii (A. Gray) Cronquist -- not accepted
  Aster foliaceus var. eatonii A. Gray -- not accepted
  Aster foliaceus var. frondeus A. Gray -- not accepted
  Aster foliaceus var. lyallii (A. Gray) Cronquist -- not accepted
  Aster foliaceus var. parryi (D.C. Eaton) A. Gray -- not accepted -- Parry's aster
  Aster fremonti (Torr. & A. Gray) A. Gray -- not accepted
  Aster fremontii (Torr. & A. Gray) A. Gray -- not accepted
  Aster fremontii var. parishii A. Gray -- not accepted
  Aster frondeus (A. Gray) Greene -- not accepted
  Aster frondosus (Nutt.) Torr. & A. Gray -- not accepted
  Aster geyeri (A. Gray) Howell -- not accepted
  Aster glabriuscula (Nutt.) Torr. & A. Gray -- not accepted
  Aster glabriuscula var. parryi (A. Gray) Onno -- not accepted
  Aster glaucescens (A. Gray) S.F. Blake -- not accepted
  Aster glaucus Torr. & A. Gray non Nees -- not accepted
  Aster gymnocephalus auct. non (DC.) A. Gray -- not accepted
  Aster hallii A. Gray -- not accepted -- Hall's aster
  Aster herveyi A. Gray -- not accepted
  Aster hesperius A. Gray -- not accepted
  Aster intricatus (A. Gray) S.F. Blake -- not accepted
  Aster johannensis var. villicaulis (A. Gray) Fernald -- not accepted
  Aster kumleinii Fr. ex A. Gray -- not accepted
  Aster laevis var. geyeri A. Gray -- not accepted -- Geyer's smooth aster
  Aster lanceolatus ssp. hesperius (A. Gray) Semple & Chmiel. -- not accepted -- Siskiyou aster
  Aster lateriflorus var. thyrsoides (A. Gray) Sheldon -- not accepted
  Aster laxifolius var. borealis Torr. & A. Gray -- not accepted
  Aster ledophyllus (A. Gray) A. Gray -- not accepted -- Cascade aster
  Aster lemmonii A. Gray -- not accepted
  Aster lindleyanus Torr. & A. Gray -- not accepted
  Aster longifolius var. villicaulis A. Gray -- not accepted
  Aster lucidulus (A. Gray) Wiegand -- not accepted
  Aster lutescens (Lindl. ex DC.) Torr. & A. Gray -- not accepted
  Aster mirabilis Torr. & A. Gray -- not accepted -- bouquet aster
  Aster missouriensis var. thyrsoides (A. Gray) Wiegand -- not accepted
  Aster multiflorus var. commutatus Torr. & A. Gray -- not accepted
  Aster multiflorus var. stricticaulis Torr. & A. Gray -- not accepted
  Aster novi-belgii var. elodes (Torr. & A. Gray) A. Gray -- not accepted -- New Belgium aster
  Aster novi-belgii var. litoreus A. Gray -- not accepted -- New Belgium aster
  Aster novi-belgii var. villicaulis (A. Gray) Boivin -- not accepted -- New Belgium aster
  Aster oblongifolius var. rigidulus A. Gray -- not accepted
  Aster occidentalis (Nutt.) Torr. & A. Gray -- not accepted -- western aster
  Aster occidentalis var. fremontii (Torr. & A. Gray) A.G. Jones -- not accepted -- Fremont's aster
  Aster occidentalis var. intermedius A. Gray -- not accepted -- intermediate aster
  Aster occidentalis var. parishii (A. Gray) Ferris -- not accepted -- Parish's aster
  Aster occidentalis var. yosemitanus (A. Gray) Cronquist -- not accepted -- Yosemite aster
  Aster oregonum (Nutt.) Torr. & A. Gray -- not accepted
  Aster oregonus auct. non (Nutt.) Torr. & A. Gray -- not accepted
  Aster palmeri A. Gray non Ericameria palmeri (A. Gray) H.M. Hall -- not accepted
  Aster pantotrichus var. thyrsoides (A. Gray) S.F. Blake -- not accepted
  Aster parryi A. Gray -- not accepted
  Aster parviflorus A. Gray non Nees -- not accepted
  Aster patens var. patentissimus (Lindl. ex DC.) Torr. & A. Gray -- not accepted -- late purple aster
  Aster pattersonii A. Gray -- not accepted
  Aster phyllolepis Torr. & A. Gray -- not accepted
  Aster pilosus var. platyphyllus (Torr. & A. Gray) S.F. Blake -- not accepted
  Aster pilosus var. pringlei (A. Gray) S.F. Blake -- not accepted -- Pringle's aster
  Aster pilosus var. pusillus (A. Gray) A.G. Jones -- not accepted
  Aster porteri A. Gray -- not accepted -- Porter's aster
  Aster potosinus A. Gray -- not accepted -- Santa Rita Mountain aster
  Aster pringlei (A. Gray) Britton -- not accepted
  Aster ptarmicoides (Nees) Torr. & A. Gray -- not accepted
  Aster ptarmicoides var. georgianus A. Gray -- not accepted
  Aster ptarmicoides var. lutescens (Lindl. ex DC.) A. Gray -- not accepted
  Aster puniceus ssp. elliottii (Torr. & A. Gray) A.G. Jones -- not accepted
  Aster puniceus var. elliottii (Torr. & A. Gray) A.G. Jones -- not accepted -- Elliott's aster
  Aster puniceus var. firmus (Nees) Torr. & A. Gray -- not accepted -- purplestem aster
  Aster puniceus var. lucidulus A. Gray -- not accepted
  Aster radula var. strictus (Pursh) A. Gray -- not accepted -- low rough aster
  Aster radulinus A. Gray -- not accepted -- roughleaf aster
  Aster sandwicensis (A. Gray) Hieron. -- not accepted
  Aster scopulorum A. Gray -- not accepted
  Aster shastensis (A. Gray) A. Gray -- not accepted
  Aster shastensis var. eradiatus A. Gray -- not accepted
  Aster sibiricus var. giganteus (Hook.) A. Gray -- not accepted -- giant arctic aster
  Aster simplex var. ramosissimus (Torr. & A. Gray) Cronquist -- not accepted
  Aster sonorae A. Gray -- not accepted
  Aster stenomeres A. Gray -- not accepted
  Aster stricticaulis (Torr. & A. Gray) Rydb. -- not accepted
  Aster subspicatus var. apricus (A. Gray) Boivin -- not accepted
  Aster subulatus var. australis (A. Gray) Shinners -- not accepted
  Aster subulatus var. sandwicensis (A. Gray) A.G. Jones -- not accepted -- annual saltmarsh aster
  Aster tenuifolius var. ramosissimus Torr. & A. Gray -- not accepted
  Aster tephrodes (A. Gray) S.F. Blake -- not accepted
  Aster tortifolius (Torr. & A. Gray) A. Gray non Michx. -- not accepted
  Aster tradescantii var. thyrsoides (A. Gray) B. Boivin -- not accepted
  Aster umbellatus var. latifolius A. Gray -- not accepted
  Aster umbellatus var. pubens A. Gray -- not accepted
  Aster undulatus var. diversifolius (Michx.) A. Gray -- not accepted
  Aster watsonii A. Gray -- not accepted
  Aster wrightii A. Gray -- not accepted
  Aster X herveyi A. Gray (pro sp.) -- not accepted -- Hervey's aster
  Aster xylorhiza (Nutt.) Torr. & A. Gray -- not accepted
  Aster yosemitanus (A. Gray) Greene -- not accepted
  Astilbe japonica (C. Morren & Decne.) A. Gray -- accepted -- florist's spiraea
  Astragalus allochrous A. Gray -- accepted -- halfmoon milkvetch
  Astragalus allochrous var. allochrous A. Gray -- not accepted -- halfmoon milkvetch
  Astragalus amphioxys A. Gray -- accepted -- Crescent milkvetch
  Astragalus amphioxys var. amphioxys A. Gray -- accepted -- Crescent milkvetch
  Astragalus andersonii A. Gray -- accepted -- Anderson's milkvetch
  Astragalus antisellii A. Gray ex W.H. Brewer & S. Watson -- not accepted
  Astragalus aridus A. Gray -- accepted -- annual desert milkvetch
  Astragalus arizonicus A. Gray -- accepted -- Arizona locoweed, Arizona milkvetch
  Astragalus arrectus A. Gray -- accepted -- Palouse milkvetch
  Astragalus arthu-schottii A. Gray -- not accepted
  Astragalus austiniae A. Gray ex W.H. Brewer & S. Watson -- accepted -- Austin's milkvetch
  Astragalus australis var. major (A. Gray) Isely -- not accepted
  Astragalus beckwithii Torr. & A. Gray -- accepted -- Beckwith's milkvetch
  Astragalus beckwithii var. beckwithii Torr. & A. Gray -- accepted -- Beckwith's milkvetch
  Astragalus bicristatus A. Gray -- accepted -- twocrested milkvetch
  Astragalus bigelovii A. Gray -- not accepted
  Astragalus bisulcatus (Hook.) A. Gray -- accepted -- two-groove milkvetch, twogrooved milkvetch
  Astragalus bisulcatus ssp. haydenianus (A. Gray) W.A. Weber -- not accepted
  Astragalus bisulcatus var. bisulcatus (Hook.) A. Gray -- accepted -- two-groove milk-vetch, twogrooved milkvetch
  Astragalus bisulcatus var. haydenianus (A. Gray) Barneby -- accepted -- Hayden milkvetch, Hayden's milkvetch
  Astragalus bolanderi A. Gray -- accepted -- Bolander's milkvetch
  Astragalus bourgovii A. Gray -- accepted -- Bourgov's milkvetch
  Astragalus breweri A. Gray -- accepted -- Brewer's milkvetch
  Astragalus caespitosus (Nutt.) A. Gray -- not accepted
  Astragalus californicus (A. Gray) Greene -- accepted -- Klamath Basin milkvetch
  Astragalus calycosus var. scaposus (A. Gray) M.E. Jones -- accepted -- scapose milkvetch, Torrey milkvetch, Torrey's milkvetch
  Astragalus casei A. Gray -- accepted -- Case's milkvetch
  Astragalus ceramicus var. filifolius (A. Gray) F.J. Herm. -- accepted -- painted milk-vetch, painted milkvetch
  Astragalus chamaeleuce A. Gray -- accepted -- cicada milkvetch
  Astragalus chamaeleuce var. chamaeleuce A. Gray -- not accepted -- cicada milkvetch
  Astragalus cobrensis A. Gray -- accepted -- copper mine milkvetch
  Astragalus cobrensis var. cobrensis A. Gray -- accepted -- copper mine milkvetch
  Astragalus confertiflorus A. Gray -- not accepted
  Astragalus confertiflorus var. confertiflorus A. Gray -- not accepted
  Astragalus cooperi A. Gray -- not accepted
  Astragalus crassicarpus var. trichocalyx (Nutt. ex Torr. & A. Gray) Barneby ex Gleason -- accepted -- groundplum milkvetch, Ozark groundplum
  Astragalus crotalariae (Benth.) A. Gray -- accepted -- rattlebox milkvetch, Salton milkvetch
  Astragalus curtipes A. Gray -- accepted -- Morro milkvetch
  Astragalus cusickii A. Gray -- accepted -- Cusick's milkvetch
  Astragalus cusickii var. cusickii A. Gray -- accepted -- Cusick's milkvetch
  Astragalus cyaneus A. Gray -- accepted -- cyanic milkvetch
  Astragalus decumbens (Nutt. ex Torr. & A. Gray) A. Gray -- not accepted
  Astragalus decumbens var. serotinus (A. Gray ex Cooper) M.E. Jones -- not accepted
  Astragalus didymocarpus var. dispermus (A. Gray) Jeps. -- accepted -- dwarf white milkvetch, Wickenburg milkvetch
  Astragalus diphysus A. Gray -- not accepted
  Astragalus dispermus A. Gray -- not accepted
  Astragalus distortus Torr. & A. Gray -- accepted -- bentpod milkvetch, Ozark milkvetch
  Astragalus distortus var. distortus Torr. & A. Gray -- accepted -- Ozark milkvetch
  Astragalus diversifolius A. Gray -- accepted -- locoweed, meadow milkvetch
  Astragalus douglasii (Torr. & A. Gray) A. Gray -- accepted -- Douglas' milkvetch, Jacumba milkvetch
  Astragalus douglasii var. douglasii (Torr. & A. Gray) A. Gray -- accepted -- Douglas's milkvetch, Jacumba milkvetch
  Astragalus douglasii var. parishii (A. Gray) M.E. Jones -- accepted -- Parish's milkvetch
  Astragalus drepanolobus A. Gray -- not accepted
  Astragalus episcopus var. lancearius (A. Gray) Isely -- not accepted -- Bishop milkvetch, bishop's milkvetch
  Astragalus filipes Torr. ex A. Gray -- accepted -- basalt milkvetch, threadstalk milkvetch
  Astragalus flavus Nutt. ex Torr. & A. Gray -- accepted -- yellow milkvetch
  Astragalus flavus var. candicans A. Gray -- not accepted
  Astragalus flexuosus var. greenei (A. Gray) Barneby -- accepted -- Greene milkvetch, Greene's milkvetch
  Astragalus fremontii A. Gray ex Torr. -- not accepted
  Astragalus frigidus (L.) A. Gray -- accepted
  Astragalus frigidus (L.) A. Gray -- not accepted
  Astragalus geyeri A. Gray -- accepted -- Geyer's milkvetch
  Astragalus geyeri var. geyeri A. Gray -- accepted -- Geyer's milkvetch
  Astragalus geyeri var. triquetrus (A. Gray) M.E. Jones -- accepted -- Geyer milkvetch, Geyer's milkvetch, Muddy River milkvetch, threecorner milkvetch
  Astragalus glabriusculus var. major A. Gray -- not accepted
  Astragalus goniatus Nutt. ex Torr. & A. Gray -- not accepted
  Astragalus greenei A. Gray -- not accepted
  Astragalus hallii A. Gray -- accepted -- Hall milkvetch, Hall's milkvetch
  Astragalus hallii var. hallii A. Gray -- accepted -- Hall milkvetch, Hall's milkvetch
  Astragalus haydenianus A. Gray -- not accepted
  Astragalus hornii A. Gray -- accepted -- Horn's milkvetch
  Astragalus howellii A. Gray -- accepted -- Howell's milkvetch
  Astragalus humillimus A. Gray -- accepted -- Mancos milk-vetch, Mancos milkvetch
  Astragalus humistratus A. Gray -- accepted -- ground-cover milkvetch, groundcover milkvetch
  Astragalus humistratus var. humistratus A. Gray -- accepted -- groundcover milkvetch
  Astragalus humistratus var. sonorae (A. Gray) M.E. Jones -- accepted -- groundcover milkvetch
  Astragalus ineptus A. Gray -- not accepted
  Astragalus kentrophyta A. Gray -- accepted -- spiny milk-vetch, spiny milkvetch
  Astragalus kentrophyta var. kentrophyta A. Gray -- accepted -- spiny milk-vetch, spiny milkvetch
  Astragalus lancearius A. Gray -- accepted -- bishop's milkvetch
  Astragalus lemmonii A. Gray -- accepted -- Lemmon's milkvetch
  Astragalus lentiformis A. Gray -- accepted -- lens pod milkvetch
  Astragalus lentiginosus var. albiflorus (A. Gray) Schoener -- not accepted
  Astragalus lentiginosus var. diphysus (A. Gray) M.E. Jones -- accepted -- double bladder freckled milkvetch, freckled milkvetch, speckledpod milkvetch
  Astragalus lentiginosus var. floribundus A. Gray -- accepted -- Carson City milkvetch, freckled milkvetch, speckledpod milkvetch
  Astragalus lentiginosus var. fremontii (A. Gray ex Torr.) S. Watson -- accepted -- Fremont's milkvetch
  Astragalus lentiginosus var. ineptus (A. Gray) M.E. Jones -- accepted -- freckled milkvetch, homely milkvetch
  Astragalus lentiginosus var. mokiacensis (A. Gray) M.E. Jones -- accepted -- Mokiak milkvetch
  Astragalus lentiginosus var. ursinus (A. Gray) Barneby -- not accepted -- Bear Valley milk-vetch
  Astragalus leptaleus A. Gray -- accepted -- park milkvetch
  Astragalus leptocarpus Torr. & A. Gray -- accepted -- rare loco milkvetch, slimpod milkvetch
  Astragalus leucopsis (Torr. & A. Gray) Torr. -- not accepted
  Astragalus lindheimeri Engelm. ex A. Gray -- accepted -- Lindheimer's milkvetch
  Astragalus lotiflorus var. reverchonii (A. Gray) M.E. Jones -- not accepted
  Astragalus lyallii A. Gray -- accepted -- Lyall's milkvetch
  Astragalus macrodon (Hook. & Arn.) A. Gray -- accepted -- Salinas milkvetch
  Astragalus malacus A. Gray -- accepted -- shaggy milkvetch
  Astragalus megacarpus (Nutt.) A. Gray -- accepted -- bladdery milkvetch, great bladdery milkvetch
  Astragalus megacarpus var. parryi A. Gray ex S. Watson -- not accepted
  Astragalus menziesii A. Gray -- not accepted
  Astragalus menziesii ssp. virgatus (A. Gray ex W.H. Brewer & S. Watson) Abrams -- not accepted
  Astragalus mexicanus var. trichocalyx (Nutt. ex Torr. & A. Gray) Fernald -- not accepted
  Astragalus microcystis A. Gray -- accepted -- dwarf milkvetch
  Astragalus miser var. decumbens (Nutt. ex Torr. & A. Gray) Cronquist -- accepted -- prostrate milkvetch
  Astragalus miser var. serotinus (A. Gray ex Cooper) Barneby -- accepted -- timber milkvetch
  Astragalus mokiacensis A. Gray -- not accepted -- Mokiak milkvetch
  Astragalus mollissimus var. bigelovii (A. Gray) Barneby -- accepted -- Bigelow's milkvetch, Bigelow's woolly locoweed, woolly locoweed
  Astragalus multiflorus (Pursh) A. Gray -- accepted -- looseflower milkvetch
  Astragalus neglectus (Torr. & A. Gray) E. Sheld. -- accepted -- Cooper's milk-vetch, Cooper's milkvetch
  Astragalus nevinii A. Gray -- accepted -- San Clemente Island milk-vetch
  Astragalus newberryi A. Gray -- accepted -- Newberry's milkvetch
  Astragalus newberryi var. newberryi A. Gray -- accepted -- Newberry's milkvetch
  Astragalus nothoxys A. Gray -- accepted -- sheep milkvetch
  Astragalus nuttallianus var. trichocarpus Torr. & A. Gray -- accepted -- hairypod milkvetch, turkey peas, turkeypeas
  Astragalus nuttallii (Torr. & A. Gray) J.T. Howell -- accepted -- Nuttall's milkvetch
  Astragalus nuttallii var. nuttallii (Torr. & A. Gray) J.T. Howell -- accepted -- Nuttall's milkvetch
  Astragalus nuttallii var. virgatus (A. Gray ex W.H. Brewer & S. Watson) Barneby -- accepted -- Nuttall's milkvetch
  Astragalus oocarpus A. Gray -- accepted -- Descanso milk-vetch, egg-pod milkvetch
  Astragalus oxyphysus A. Gray -- accepted -- Mt. Diablo milkvetch
  Astragalus pachycarpus Torr. & A. Gray -- not accepted
  Astragalus palmeri A. Gray -- accepted -- Palmer's milkvetch
  Astragalus parishii A. Gray -- not accepted
  Astragalus parryi A. Gray -- accepted -- Parry's milkvetch
  Astragalus pattersonii A. Gray -- accepted -- Patterson milkvetch, Patterson's milkvetch
  Astragalus platytropis A. Gray -- accepted -- broadkeel milkvetch, broadkeeled milkvetch
  Astragalus preussii A. Gray -- accepted -- Preuss' milkvetch
  Astragalus preussii var. laxiflorus A. Gray -- accepted -- Preuss milkvetch, Preuss' milkvetch
  Astragalus preussii var. preussii A. Gray -- accepted -- Preuss milkvetch, Preuss' milkvetch
  Astragalus pubentissimus Torr. & A. Gray -- accepted -- Green River milkvetch
  Astragalus pubentissimus var. pubentissimus Torr. & A. Gray -- accepted -- Green River milkvetch
  Astragalus pulsiferae A. Gray -- accepted -- Ames' milkvetch
  Astragalus pulsiferae var. pulsiferae A. Gray -- accepted -- Ames' milkvetch
  Astragalus pycnostachyus A. Gray -- accepted -- marsh milkvetch
  Astragalus pycnostachyus var. pycnostachyus A. Gray -- accepted -- marsh milkvetch
  Astragalus rattanii A. Gray -- accepted -- Rattan's milkvetch
  Astragalus rattanii var. rattanii A. Gray -- accepted -- Rattan's milkvetch
  Astragalus reflexus Torr. & A. Gray -- accepted -- drooping milkvetch
  Astragalus reventus A. Gray -- accepted -- Blue Mountain milkvetch
  Astragalus reverchonii A. Gray -- not accepted
  Astragalus robbinsii (Oakes) A. Gray -- accepted -- Robbins' milkvetch
  Astragalus robbinsii var. robbinsii (Oakes) A. Gray -- accepted -- Robbins milk-vetch, Robbins' milkvetch
  Astragalus sabulonum A. Gray -- accepted -- gravel milkvetch
  Astragalus sclerocarpus A. Gray -- accepted -- woodypod milkvetch
  Astragalus sericoleucus A. Gray -- accepted -- silky milkvetch
  Astragalus sericoleucus var. tridactylicus (A. Gray) M.E. Jones -- not accepted
  Astragalus serotinus A. Gray ex Cooper -- not accepted
  Astragalus simplicifolius (Nutt.) A. Gray -- accepted -- little bun milkvetch
  Astragalus spaldingii A. Gray -- accepted -- Spalding's milkvetch
  Astragalus sparsiflorus A. Gray -- accepted -- Front Range milkvetch
  Astragalus sparsiflorus var. majusculus A. Gray -- accepted -- Front Range milkvetch, tium milkvetch
  Astragalus sparsiflorus var. sparsiflorus A. Gray -- accepted -- Front Range milkvetch
  Astragalus speirocarpus A. Gray -- accepted -- threadstalk milkvetch
  Astragalus stenophyllis Torr. & A. Gray -- not accepted
  Astragalus stenophyllus Torr. & A. Gray -- not accepted
  Astragalus stenophyllus var. filipes (Torr. ex A. Gray) Tidestr. -- not accepted
  Astragalus subcinereus A. Gray -- accepted -- Silver's milkvetch
  Astragalus subcinereus var. subcinereus A. Gray -- accepted -- Kaibab Plateau milkvetch
  Astragalus tener A. Gray -- accepted -- alkali milkvetch
  Astragalus tener var. tener A. Gray -- accepted -- alkali milkvetch
  Astragalus tennesseensis A. Gray ex Chapm. -- accepted -- Tennessee milkvetch
  Astragalus tephrodes A. Gray -- accepted -- ashen milkvetch
  Astragalus tephrodes var. brachylobus (A. Gray) Barneby -- accepted -- ashen milkvetch, Prescott milkvetch
  Astragalus tephrodes var. remulcus (A. Gray) Barneby -- accepted -- ashen milkvetch
  Astragalus tephrodes var. tephrodes A. Gray -- accepted -- ashen milkvetch
  Astragalus tetrapterus A. Gray -- accepted -- four-wing milkvetch, fourwing milkvetch
  Astragalus thurberi A. Gray -- accepted -- Thurber's milkvetch
  Astragalus tricarinatus A. Gray -- accepted -- triple-ribbed milkvetch, triplerib milkvetch
  Astragalus trichocalyx Nutt. ex Torr. & A. Gray -- not accepted
  Astragalus trichopodus (Nutt.) A. Gray -- accepted -- Santa Barbara milkvetch
  Astragalus trichopodus ssp. antisellii (A. Gray ex W.H. Brewer & S. Watson) Thorne -- not accepted
  Astragalus trichopodus ssp. leucopsis (Torr. & A. Gray) Thorne -- not accepted
  Astragalus trichopodus var. antisellii (A. Gray ex W.H. Brewer & S. Watson) Jeps. -- accepted -- Antisell's milkvetch, Santa Barbara milkvetch
  Astragalus trichopodus var. trichopodus (Nutt.) A. Gray -- accepted -- Santa Barbara milkvetch
  Astragalus tridactylicus A. Gray -- accepted -- foothill milkvetch
  Astragalus triquetrus A. Gray -- not accepted
  Astragalus utahensis (Torr.) Torr. & A. Gray -- accepted -- Utah locoweed, Utah milkvetch
  Astragalus vaccarum A. Gray -- accepted -- Cow Spring milkvetch
  Astragalus viridis (Nutt. ex Torr. & A. Gray) E. Sheld. -- not accepted
  Astragalus wardii A. Gray -- accepted -- Ward's milkvetch
  Astragalus webberi A. Gray ex W.H. Brewer & S. Watson -- accepted -- Webber's milk-vetch
  Astragalus whitneyi A. Gray -- accepted -- balloon milkvetch, balloonpod milkvetch
  Astragalus whitneyi ssp. hookerianus (Torr. & A. Gray) Abrams -- not accepted
  Astragalus whitneyi var. whitneyi A. Gray -- accepted -- balloonpod milkvetch, Whitney's milkvetch
  Astragalus wrightii A. Gray -- accepted -- Wright's milkvetch
  Astrichoseris A. Gray -- not accepted
  Astrichoseris platyphylla A. Gray -- not accepted
  Astronidium A. Gray -- accepted
  Astronidium pickeringii (A. Gray) Christoph. -- accepted
  Atrichoseris A. Gray -- accepted -- atrichoseris
  Atrichoseris platyphylla (A. Gray) A. Gray -- accepted -- gravel ghost, parachute plant, parachute-plant
  Atriplex brandegeei (A. Gray) Collotzi ex W.A. Weber -- not accepted
  Atriplex patula var. hastata auct. non (L.) A. Gray -- not accepted
  Atriplex patula var. littoralis (L.) A. Gray -- not accepted
  Atriplex truncata (Torr. ex S. Watson) A. Gray -- accepted -- wedgescale saltbush
  Atropis californica Munro ex A. Gray -- not accepted
  Avena smithii Porter ex A. Gray -- not accepted
  Ayenia microphylla A. Gray -- accepted -- dense ayenia, shrubby ayenia
  Azalea californica Torr. & A. Gray ex Durand -- not accepted
  Azalea japonica A. Gray -- not accepted
  Azalea occidentalis Torr. & A. Gray ex Torr. -- not accepted
  Azalea vaseyi (A. Gray) Rehder -- not accepted
  Baccharis bigelovii A. Gray -- accepted -- Bigelow baccharis, Bigelow's false willow, Bigelow's falsewillow
  Baccharis brachyphylla A. Gray -- accepted -- shortleaf baccharis
  Baccharis emoryi A. Gray -- not accepted -- Emory's baccharis
  Baccharis havardii A. Gray -- accepted -- Havard's false willow, Havard's falsewillow
  Baccharis plummerae A. Gray -- accepted -- Plummer's baccharis
  Baccharis plummerae ssp. plummerae A. Gray -- accepted -- Plummer's baccharis
  Baccharis salicina Torr. & A. Gray -- accepted -- Emory's baccharis, Great Plains false willow, Great Plains falsewillow, willow baccharis
  Baccharis sarothroides A. Gray -- accepted -- broom baccharis, desert broom, desertbroom
  Baccharis sergiloides A. Gray -- accepted -- desert baccharis, squaw waterweed baccharis
  Baccharis texana (Torr. & A. Gray) A. Gray -- accepted -- prairie baccharis, prairie false willow, prairie falsewillow
  Baccharis wrightii A. Gray -- accepted -- Wright's baccharis
  Baeothryon clintonii (A. Gray) Á. Löve & D. Löve -- not accepted
  Baeria debilis Greene ex A. Gray -- not accepted
  Baeria fremontii (Torr. ex A. Gray) A. Gray -- not accepted
  Baeria leptalea (A. Gray) A. Gray -- not accepted
  Baeria macrantha (A. Gray) A. Gray -- not accepted
  Baeria macrantha var. pauciaristata A. Gray -- not accepted
  Baeria maritima A. Gray -- not accepted
  Baeria minor ssp. maritima (A. Gray) Ferris -- not accepted
  Baeria platycarpha (A. Gray) A. Gray -- not accepted
  Baeria uliginosa (Nutt.) A. Gray -- not accepted
  Bahia absinthifolia var. dealbata (A. Gray) A. Gray -- not accepted -- Dealbata's bahia
  Bahia bigelovii A. Gray -- accepted -- Bigelow's bahia
  Bahia biternata A. Gray -- accepted -- slim-lobe false goldfields, slimlobe bahia
  Bahia dissecta (A. Gray) Britton -- not accepted -- ragleaf bahia
  Bahia neomexicana (A. Gray) A. Gray -- not accepted
  Bahia nudicaulis A. Gray -- not accepted
  Bahia nudicaulis var. oblongifolia (A. Gray) Cronquist -- not accepted
  Bahia oblongifolia (A. Gray) A. Gray -- not accepted
  Bahia oppositifolia (Nutt.) A. Gray -- not accepted
  Bahia pedata A. Gray -- accepted -- blunt-scale false goldfields, bluntscale bahia
  Bahia wallacei A. Gray -- not accepted
  Bahia woodhousei (A. Gray) A. Gray -- not accepted
  Bahiopsis laciniata (A. Gray) E.E. Schill. & Panero -- accepted -- torhleaf goldeneye
  Baileya Harv. & A. Gray ex A. Gray -- accepted -- baileya, desert marigold
  Baileya multiradiata Harv. & A. Gray ex A. Gray -- accepted -- desert baileya, desert marigold
  Baileya multiradiata var. pleniradiata (Harv. & A. Gray ex A. Gray) Coville -- not accepted
  Baileya pauciradiata Harv. & A. Gray ex A. Gray -- accepted -- laxflower
  Baileya pleniradiata Harv. & A. Gray ex A. Gray -- accepted -- desertmarigold baileya, woolly desert marigold, woolly desert-marigold
  Balsamorhiza bolanderi A. Gray -- not accepted
  Balsamorhiza careyana A. Gray -- accepted -- Carey's balsamroot, intermediate balsamroot
  Balsamorhiza careyana var. careyana A. Gray -- not accepted -- Carey's balsamroot
  Baptisia bracteata var. laevicaulis (A. Gray ex Canby) Isely -- not accepted -- longbract wild indigo
  Baptisia laevicaulis (A. Gray ex Canby) Small -- not accepted
  Baptisia lecontei Torr. & A. Gray -- accepted -- pineland wild indigo
  Baptisia leucantha Torr. & A. Gray -- not accepted
  Baptisia leucophaea var. laevicaulis A. Gray ex Canby -- not accepted
  Baptisia megacarpa Chapm. ex Torr. & A. Gray -- accepted -- Apalachicola wild indigo
  Barringtonia samoensis A. Gray -- accepted
  Bartlettia A. Gray -- accepted -- bartlettia
  Bartlettia scaposa A. Gray -- accepted -- Bartlett daisy
  Bauhinia lunarioides A. Gray ex S. Watson -- accepted -- Texasplume
  Beckmannia eruciformis var. uniflora Scribn. ex A. Gray -- not accepted
  Beckmannia syzigachne var. uniflora (Scribn. ex A. Gray) B. Boivin -- not accepted
  Beckwithia andersonii (A. Gray) Jeps. -- not accepted
  Benthamantha edwardsii var. glabella (A. Gray) Wiggins -- not accepted
  Benthamantha glabella (A. Gray) Rydb. -- not accepted
  Berberis fendleri A. Gray -- accepted -- Colorado barberry
  Berberis nevinii A. Gray -- accepted -- Nevin's barberry
  Berlandiera dealbata (Torr. & A. Gray) Small -- not accepted
  Berlandiera incisa Torr. & A. Gray -- not accepted
  Berlandiera lyrata var. macrophylla A. Gray -- not accepted
  Berlandiera texana var. bentonicifolia (Hook.) Torr. & A. Gray -- not accepted
  Berlandiera texana var. betonicifolia (Hook.) Torr. & A. Gray -- not accepted
  Berlandiera tomentosa var. dealbata Torr. & A. Gray -- not accepted
  Berlandiera X macrophylla (A. Gray) M.E. Jones -- accepted
  Besseya alpina (A. Gray) Rydb. -- not accepted -- alpine besseya
  Bidens aristosa var. mutica (A. Gray) Gattinger -- not accepted
  Bidens aurea var. wrightii (A. Gray) Sherff -- not accepted
  Bidens bigelovii A. Gray -- accepted -- Bigelow beggarticks, Bigelow's beggarticks, stickseed
  Bidens bigelovii var. bigelovii A. Gray -- not accepted
  Bidens cernua var. elata Torr. & A. Gray -- not accepted
  Bidens comosa (A. Gray) Wiegand -- not accepted
  Bidens coronata var. tenuiloba (A. Gray) Sherff -- not accepted
  Bidens cosmoides (A. Gray) Sherff -- accepted -- cosmosflower beggarticks
  Bidens discoidea (Torr. & A. Gray) Britton -- accepted -- discoid beggarticks, small beggarticks, swamp beggar-ticks
  Bidens elata (Torr. & A. Gray) Sherff -- not accepted
  Bidens hawaiensis A. Gray -- accepted -- Hawai'i beggarticks
  Bidens heterosperma A. Gray -- accepted -- Rocky Mountain beggarticks
  Bidens lemmonii A. Gray -- accepted -- Lemmon's beggarticks
  Bidens macrocarpa (A. Gray) Sherff -- accepted -- largefruit beggarticks
  Bidens macrocarpa var. ovatifolia (A. Gray) Sherff -- not accepted
  Bidens mauiensis (A. Gray) Sherff -- accepted -- Maui beggarticks
  Bidens menziesii (A. Gray) Sherff -- accepted -- Mauna Loa beggarticks
  Bidens menziesii ssp. menziesii (A. Gray) Sherff -- accepted -- Mauna Loa beggarticks
  Bidens tenuisecta A. Gray -- accepted -- slim-lobe beggarticks, slimlobe beggarticks
  Bigelovia brachylepis A. Gray -- not accepted
  Bigelovia intricata A. Gray -- not accepted
  Bigelovia vaseyi A. Gray -- not accepted
  Bilderdykia cristata (Engelm. & A. Gray) Greene -- not accepted
  Bilderdykia scandens var. cristata (Engelm. & A. Gray) C.F. Reed -- not accepted
  Biltia vaseyi (A. Gray) Small -- not accepted
  Blephariglotis peramoena (A. Gray) Rydb. -- not accepted
  Blephariglottis peramoena (A. Gray) Rydb. -- not accepted
  Blepharipappus scaber ssp. laevis (A. Gray) D.D. Keck -- not accepted -- rough eyelashweed
  Bobea brevipes A. Gray -- accepted -- `akupa
  Bobea elatior var. brevipes (A. Gray) Hillebr. -- not accepted
  Bobea sandwicensis (A. Gray) Hillebr. -- accepted -- 'ahakea, Hawai'i dogweed
  Boechera brachycarpa (Torr. & A. Gray) Dorn -- not accepted
  Boechera drummondii (A. Gray) Á. Löve & D. Löve -- not accepted
  Boechera platysperma (A. Gray) Al-Shehbaz -- accepted -- pioneer rockcress
  Boerhavia eriosolena A. Gray -- not accepted
  Boerhavia linearifolia A. Gray -- accepted -- narrowleaf spiderling
  Boerhavia purpurascens A. Gray -- accepted -- purple spiderling
  Boerhavia wrightii A. Gray -- accepted -- large-bract spiderling, largebract spiderling, Wright's boerhavia
  Boisduvalia densiflora var. salicina (Nutt. ex Torr. & A. Gray) Munz -- not accepted
  Boisduvalia salicina (Nutt. ex Torr. & A. Gray) Rydb. -- not accepted
  Boisduvalia stricta (A. Gray) Greene -- not accepted
  Bolandra A. Gray -- accepted -- false coolwort
  Bolandra californica A. Gray -- accepted -- Sierra false coolwort
  Boltonia asteroides var. decurrens (Torr. & A. Gray) Fernald -- not accepted
  Boltonia asteroides var. latisquama (A. Gray) Cronquist -- accepted -- white doll's daisy, white doll's-daisy
  Boltonia decurrens (Torr. & A. Gray) Alph. Wood -- accepted -- claspingleaf doll's daisy, decurrent false aster
  Boltonia latisquama A. Gray -- not accepted
  Boltonia latisquama var. decurrens (Torr. & A. Gray) Fernald & Grisc. -- not accepted
  Boltonia latisquama var. occidentalis A. Gray -- not accepted
  Bombycilaena californica var. subvestita (A. Gray) Kartesz -- not accepted
  Bonamia aquatica (Walter) A. Gray -- not accepted
  Bonamia grandiflora (A. Gray) Hallier f. -- accepted -- Florida bonamia, Florida lady's nightcap
  Bonamia humistrata (Walter) A. Gray -- not accepted
  Bonamia menziesii A. Gray -- accepted -- Hawaii lady's nightcap
  Bonamia pickeringii (Torr. ex M.A. Curtis) A. Gray -- not accepted
  Boschniakia strobilacea A. Gray -- not accepted -- California groundcone
  Bouchea linifolia A. Gray -- accepted -- groovestem bouchea
  Bouteloua curtipendula var. aristosa A. Gray -- not accepted
  Bouteloua oligostachya (Nutt.) Torr. ex A. Gray -- not accepted
  Bouteloua racemosa var. aristosa (A. Gray) S. Watson & J.M. Coult. -- not accepted
  Boykinia major A. Gray -- accepted -- large boykinia
  Boykinia occidentalis Torr. & A. Gray -- accepted -- coast boykinia, coastal brookfoam
  Boykinia ranunculifolia (Hook.) A. Gray -- not accepted
  Boykinia rotundifolia Parry ex A. Gray -- accepted -- roundleaf brookfoam
  Brachyactis frondosa (Nutt.) A. Gray -- not accepted -- leafy rayless aster
  Brachyelytrum aristatum var. engelmannii A. Gray -- not accepted
  Brachystigma wrightii (A. Gray) Pennell -- accepted -- Arizona desert foxglove, Wright's brachystigma
  Bradburia hirtella Torr. & A. Gray -- accepted -- Texas chrysopsis
  Brazoria Engelm. & A. Gray -- accepted -- brazos-mint, brazosmint
  Brazoria scutellarioides Engelm. & A. Gray -- not accepted -- prairie brazosmint
  Brazoria truncata (Benth.) Engelm. & A. Gray -- accepted -- rattlesnake flower
  Brazoria truncata var. truncata (Benth.) Engelm. & A. Gray -- accepted -- rattlesnake flower
  Breweria aquatica (Walter) A. Gray -- not accepted
  Breweria humistrata (Walter) A. Gray -- not accepted
  Breweria ovalifolia (Torr.) A. Gray -- not accepted
  Breweria pickeringii (Torr. ex M.A. Curtis) A. Gray -- not accepted
  Brickellia amplexicaulis var. lanceolata (A. Gray) B.L. Rob. -- not accepted -- earleaf brickellbush
  Brickellia atractyloides A. Gray -- accepted -- hollyleaf brickellbush, spearleaf brickellbush
  Brickellia atractyloides var. atractyloides A. Gray -- accepted -- spearleaf brickellia
  Brickellia baccharidea A. Gray -- accepted -- baccharis-leaf brickellia, baccharisleaf brickellbush, resinleaf brickellbush
  Brickellia betonicifolia A. Gray -- accepted -- betonyleaf brickellbush
  Brickellia brachiata A. Gray -- not accepted
  Brickellia brachyphylla (A. Gray) A. Gray -- accepted -- Brach brickellbush, plumed brickellbush
  Brickellia brachyphylla var. brachyphylla (A. Gray) A. Gray -- not accepted -- plumed brickellbush
  Brickellia californica (Torr. & A. Gray) A. Gray -- accepted -- California brickellbush, Jepson's brickellbush
  Brickellia californica var. californica (Torr. & A. Gray) A. Gray -- not accepted -- California brickellbush
  Brickellia coulteri A. Gray -- accepted -- Coulter's brickellbush
  Brickellia coulteri var. brachiata (A. Gray) B.L. Turner -- accepted
  Brickellia coulteri var. coulteri A. Gray -- accepted -- Coulter's brickellbush
  Brickellia cylindracea A. Gray & Engelm. -- accepted -- gravelbar brickellbush
  Brickellia diffusa (Vahl) A. Gray -- accepted
  Brickellia eupatorioides var. corymbulosa (Torr. & A. Gray) Shinners -- accepted -- false boneset
  Brickellia eupatorioides var. gracillima (A. Gray) B.L. Turner -- accepted -- false boneset
  Brickellia fendleri A. Gray -- not accepted -- Fendler's brickellbush
  Brickellia floribunda A. Gray -- accepted -- Chihuahuan brickellbush, desert brickellbush
  Brickellia frutescens A. Gray -- accepted -- rigid brickellbush, shrubby brickellbush
  Brickellia grandiflora var. petiolaris A. Gray -- not accepted
  Brickellia greenei A. Gray -- accepted -- Greene's brickellbush
  Brickellia incana A. Gray -- accepted -- white brickellbush, woolly brickellbush
  Brickellia laciniata A. Gray -- accepted -- splitleaf brickellbush
  Brickellia lemmonii A. Gray -- accepted -- Lemmon's brickellbush
  Brickellia lemmonii var. lemmonii A. Gray -- accepted -- Lemmon's brickellbush
  Brickellia microphylla (Nutt.) A. Gray -- accepted -- littleleaf brickellbush
  Brickellia microphylla ssp. scabra (A. Gray) W.A. Weber -- not accepted
  Brickellia microphylla var. microphylla (Nutt.) A. Gray -- accepted -- littleleaf brickellbush, Watson's brickellbush
  Brickellia microphylla var. scabra A. Gray -- accepted -- rough brickellbush
  Brickellia nevinii A. Gray -- accepted -- Nevin's brickellbush
  Brickellia parvula A. Gray -- accepted -- Mt. Davis brickellbush, small brickellbush, small brickellia
  Brickellia pringlei A. Gray -- accepted -- Pringle's brickellbush
  Brickellia rusbyi A. Gray -- accepted -- stinking brickellbush
  Brickellia scabra (A. Gray) A. Nelson ex B.L. Rob. -- not accepted
  Brickellia shaffneri (A. Gray) Shinners -- not accepted
  Brickellia simplex A. Gray -- accepted -- Sonoran brickellbush
  Brickellia squamulosa A. Gray -- not accepted -- Mule Mountain brickellbush
  Brickellia veronicifolia (Kunth) A. Gray -- accepted -- veronicaleaf brickellbush
  Brickellia veronicifolia var. veronicifolia (Kunth) A. Gray -- not accepted -- veronicaleaf brickellbush
  Brickelliastrum fendleri (A. Gray) King & H. Rob. -- accepted -- Fendler's brickellbush
  Brighamia A. Gray -- accepted
  Brighamia insignis A. Gray -- accepted -- `olulu, cabbage on a stick
  Brizopyrum spicatum var. strictum (Torr.) A. Gray ex S. Watson -- not accepted
  Bromelica smithii (Porter ex A. Gray) Farw. -- not accepted
  Bromopsis kalmii (A. Gray) Holub -- not accepted
  Bromus ciliatus var. purgans (L.) A. Gray -- not accepted
  Bromus kalmii A. Gray -- accepted -- arctic brome, brome de Kalm, Kalm's brome, wild chess
  Bromus muticus Nutt. ex A. Gray -- not accepted
  Bromus nitens Nutt. ex A. Gray -- not accepted
  Bromus parviflorus Nutt. ex A. Gray -- not accepted
  Bryanthus breweri A. Gray -- not accepted
  Buchnera arizonica (A. Gray) Pennell -- not accepted -- Arizona bluehearts
  Bumelia lanuginosa ssp. rigida (A. Gray) Cronquist -- not accepted
  Bumelia lanuginosa var. rigida A. Gray -- not accepted
  Bumelia rigida (A. Gray) Small -- not accepted
  Bursera microphylla A. Gray -- accepted -- elephant tree, littleleaf elephant tree
  Cabomba caroliniana A. Gray -- accepted -- Carolina fanwort, fanwort
  Cabomba caroliniana var. caroliniana A. Gray -- not accepted -- Carolina fanwort, fanwort
  Cacalia decomposita A. Gray -- not accepted
  Cacalia diversifolia Torr. & A. Gray -- not accepted
  Cacalia floridana A. Gray -- not accepted
  Cacalia nardosmia A. Gray -- not accepted
  Cacalia rugelia (A. Gray) T.M. Barkley & Cronquist -- not accepted
  Cacaliopsis A. Gray -- accepted -- cacaliopsis
  Cacaliopsis nardosmia (A. Gray) A. Gray -- accepted -- silvercrown
  Caesalpinia brachycarpa (A. Gray) Fisher -- not accepted -- broad-pod rushpea, broadpod nicker
  Caesalpinia caudata (A. Gray) Fisher -- accepted -- tailed nicker
  Caesalpinia drepanocarpa (A. Gray) Fisher -- not accepted -- sickle-pod holdback, sicklepod holdback, sicklepod rushpea
  Caesalpinia drummondii (Torr. & A. Gray) Fisher -- not accepted -- dwarf nicker
  Caesalpinia jamesii (Torr. & A. Gray) Fisher -- not accepted -- James' holdback, James' rushpea
  Caesalpinia mexicana A. Gray -- not accepted -- Mexican holdback, Mexican poinciana
  Calamagrostis albescens Buckley ex A. Gray -- not accepted
  Calamagrostis breviseta (A. Gray) Scribn. -- not accepted
  Calamagrostis columbiensis Nutt. ex A. Gray -- not accepted
  Calamagrostis inexpansa A. Gray -- not accepted
  Calamagrostis inexpansa var. inexpansa A. Gray -- not accepted
  Calamagrostis neglecta ssp. inexpansa (A. Gray) Tzvelev -- not accepted
  Calamagrostis neglecta var. inexpansa (A. Gray) M.E. Jones -- not accepted
  Calamagrostis pallida Nutt. ex A. Gray -- not accepted
  Calamagrostis pickeringii A. Gray -- accepted -- Pickering's reedgrass
  Calamagrostis pickeringii f. pickeringii A. Gray -- accepted
  Calamagrostis pickeringii var. pickeringii A. Gray -- not accepted
  Calamagrostis porteri A. Gray -- accepted -- Porter's reedgrass
  Calamagrostis porteri ssp. porteri A. Gray -- accepted -- Porter's reedgrass
  Calamagrostis stricta ssp. inexpansa (A. Gray) C.W. Greene -- accepted -- northern reedgrass, slim-stem reed grass
  Calamagrostis sylvatica var. breviseta A. Gray -- not accepted
  Calamintha canescens Torr. & A. Gray ex Benth. -- not accepted
  Calamintha ilicifolia A. Gray -- not accepted
  Calamovilfa (A. Gray) Hack. ex Scribn. & Southw. -- accepted -- sandreed
  Calandrinia tweedyi A. Gray -- not accepted
  Calliandra herbacea Engelm. ex A. Gray -- not accepted
  Calliandra humilis var. reticulata (A. Gray) L.D. Benson -- accepted -- dwarf stickpea
  Calliandra reticulata A. Gray -- not accepted
  Callirhoe alcaeoides (Michx.) A. Gray -- accepted -- light poppymallow, plains poppymallow
  Callirhoe involucrata (Torr. & A. Gray) A. Gray -- accepted -- low poppymallow, purple poppy mallow, purple poppymallow, winecup
  Callirhoe involucrata var. involucrata (Torr. & A. Gray) A. Gray -- accepted -- purple poppy mallow, purple poppymallow
  Callirhoe involucrata var. lineariloba (Torr. & A. Gray) A. Gray -- accepted -- purple poppymallow
  Callirhoe papaver (Cav.) A. Gray -- accepted -- woodland poppymallow, woods poppymallow
  Callirhoe pedata (Nutt. ex Hook.) A. Gray -- accepted -- palmleaf poppymallow
  Callirhoe triangulata (Leavenw.) A. Gray -- accepted -- clustered poppymallow
  Calochortus nuttallii Torr. & A. Gray -- accepted -- sego lily, sego-lily
  Calophanes angusta A. Gray -- not accepted
  Calophanes decumbens A. Gray -- not accepted
  Calophanes linearis (Torr. & A. Gray) A. Gray -- not accepted
  Caltha palustris var. flabellifolia (Pursh) Torr. & A. Gray -- not accepted
  Calycadenia fremontii A. Gray -- accepted -- Fremont's western rosinweed
  Calycadenia mollis A. Gray -- accepted -- soft western rosinweed
  Calycadenia pauciflora A. Gray -- accepted -- smallflower western rosinweed
  Calycadenia tenella (Nutt.) Torr. & A. Gray -- not accepted
  Calycanthus floridus var. glaucus (Willd.) Torr. & A. Gray -- accepted -- eastern sweetshrub
  Calycanthus floridus var. laevigatus (Willd.) Torr. & A. Gray -- not accepted
  Calycocarpum lyonii (Pursh) A. Gray -- accepted -- cupseed
  Calycoseris A. Gray -- accepted -- tackstem
  Calycoseris parryi A. Gray -- accepted -- yellow tackstem
  Calycoseris wrightii A. Gray -- accepted -- white tackstem
  Calylophus berlandieri ssp. pinifolius (Engelm. ex A. Gray) Towner -- not accepted -- Berlandier's sundrops
  Calylophus hartwegii ssp. fendleri (A. Gray) Towner & P.H. Raven -- not accepted -- Fendler calylophus, Hartweg's sundrops
  Calylophus hartwegii ssp. lavandulifolius (Torr. & A. Gray) Towner & P.H. Raven -- not accepted
  Calylophus hartwegii ssp. pubescens (A. Gray) Towner & P.H. Raven -- not accepted -- hairy calylophus, Hartweg's sundrops
  Calylophus hartwegii var. lavandulifolius (Torr. & A. Gray) Shinners -- not accepted
  Calylophus hartwegii var. pubescens (A. Gray) Shinners -- not accepted
  Calylophus lavandulifolius (Torr. & A. Gray) P.H. Raven -- not accepted -- lavender calylophus, lavender sundrop, lavenderleaf eveningprimrose, lavenderleaf sundrops
  Calylophus serrulatus var. spinulosus (Nutt. ex Torr. & A. Gray) Shinners -- not accepted
  Calylophus tubicula (A. Gray) P.H. Raven -- not accepted -- Texas sundrops
  Calymmandra candida Torr. & A. Gray -- not accepted
  Calyptridium parryi A. Gray -- not accepted
  Calyptridium parryi var. parryi A. Gray -- not accepted -- pussypaws
  Calyptridium umbellatum var. caudiciferum (A. Gray) Jeps. -- not accepted
  Calystegia fulcrata (A. Gray) Brummitt -- not accepted
  Calystegia occidentalis (A. Gray) Brummitt -- accepted -- chaparral false bindweed
  Calystegia occidentalis ssp. fulcrata (A. Gray) Brummitt -- accepted -- chaparral false bindweed
  Calystegia occidentalis ssp. occidentalis (A. Gray) Brummitt -- accepted -- chaparral false bindweed
  Calystegia occidentalis ssp. occidentalis var. occidentalis (A. Gray) Brummitt -- not accepted -- chaparral false bindweed
  Calystegia occidentalis var. occidentalis (A. Gray) Brummitt -- accepted -- chaparral false bindweed
  Calystegia sepium var. pubescens A. Gray -- not accepted
  Calystegia sepium var. repens (L.) A. Gray -- not accepted
  Calystegia spithamaea var. pubescens (A. Gray) C.F. Reed -- not accepted
  Calytophus berlandieri var. pinifolius (Engelm. ex A. Gray) Towner -- not accepted
  Calytophus hartwegii var. fendleri (A. Gray) Towner & P.H. Raven -- not accepted
  Calytophus hartwegii var. pubescens (A. Gray) Towner & P.H. Raven -- not accepted
  Calytophus lavandulifolius (Torr. & A. Gray) P.H. Raven -- not accepted
  Calytophus tubicula (A. Gray) P.H. Raven -- not accepted
  Camassia angusta (Engelm. & A. Gray) Blank. -- accepted -- prairie camas
  Camissonia bistorta (Nutt. ex Torr. & A. Gray) P.H. Raven -- not accepted -- southern suncup
  Camissonia breviflora (Torr. & A. Gray) P.H. Raven -- not accepted -- fewflower evening primrose, fewflower evening-primrose, shortflower suncup
  Camissonia brevipes (A. Gray) P.H. Raven -- not accepted -- golden suncup, yellow cups
  Camissonia brevipes ssp. brevipes (A. Gray) P.H. Raven -- not accepted -- golden suncup
  Camissonia californica (Nutt. ex Torr. & A. Gray) P.H. Raven -- not accepted -- California primrose, California suncup
  Camissonia chamaenerioides (A. Gray) P.H. Raven -- not accepted -- long-capsule suncup, longcapsule suncup, willowherb suncup
  Camissonia ovata (Nutt. ex Torr. & A. Gray) P.H. Raven -- not accepted -- goldeneggs
  Camissonia parvula (Nutt. ex Torr. & A. Gray) P.H. Raven -- accepted -- Lewis River suncup
  Camissonia scapoidea (Torr. & A. Gray) P.H. Raven -- not accepted -- barestem eveningprimrose, Paiute suncup, scapoid suncup
  Camissonia scapoidea ssp. scapoidea (Torr. & A. Gray) P.H. Raven -- not accepted -- Paiute suncup, Seorsa evening primrose, Seorsa eveningprimrose
  Camissonia tanacetifolia (Torr. & A. Gray) P.H. Raven -- not accepted -- tansyleaf evening primrose, tansyleaf evening-primrose, tansyleaf suncup
  Camissonia tanacetifolia ssp. tanacetifolia (Torr. & A. Gray) P.H. Raven -- not accepted -- tansyleaf evening primrose, tansyleaf evening-primrose, tansyleaf suncup
  Camissoniopsis bistorta (Nutt. ex Torr. & A. Gray) W.L. Wagner & Hoch -- accepted -- southern suncup
  Campanula alaskana (A. Gray) W. Wight ex J.P. Anderson -- accepted
  Campanula floridana S. Watson ex A. Gray -- accepted -- Florida bellflower
  Campanula parryi A. Gray -- accepted -- Parry's bellflower, Parry's harebell
  Campanula parryi var. parryi A. Gray -- accepted -- Parry's bellflower
  Campanula reverchonii A. Gray -- accepted -- basin bellflower
  Campanula rotundifolia var. alaskana A. Gray -- not accepted
  Canavalia sericea A. Gray -- accepted -- silky jackbean
  Canbya Parry ex A. Gray -- accepted -- pygmypoppy
  Canbya candida Parry ex A. Gray -- accepted -- white pygmypoppy
  Capnoides micranthum (Engelm. ex A. Gray) Britton -- not accepted
  Cardamine clematitis Shuttlw. ex A. Gray -- accepted -- mountain bittercress, small mountain bittercress
  Cardamine cordifolia A. Gray -- accepted -- heartleaf bittercress, large mountain bittercress
  Cardamine cordifolia var. cordifolia A. Gray -- not accepted -- heartleaf bittercress
  Cardamine cordifolia var. incana A. Gray ex M.E. Jones -- not accepted -- heartleaf bittercress
  Carduus americanus (A. Gray) Rydb. -- not accepted
  Carduus lecontei (Torr. & A. Gray) Pollard -- not accepted
  Carex aestivalis M.A. Curtis ex A. Gray -- accepted -- summer sedge
  Carex debilis ssp. pubera (A. Gray) Á. Löve & D. Löve -- not accepted
  Carex debilis var. pubera A. Gray -- not accepted -- white edge sedge
  Carex emmonsii var. muehlenbergii (A. Gray) Rettig -- not accepted
  Carex emmonsii var. muhlenbergii (A. Gray) Rettig -- not accepted
  Carex grayi var. hispidula A. Gray -- not accepted
  Carex lupulina var. pedunculata A. Gray -- not accepted
  Carex nigromarginata var. muehlenbergii (A. Gray) Gleason -- not accepted
  Carex nigromarginata var. muhlenbergii (A. Gray) Gleason -- not accepted
  Carlowrightia A. Gray -- accepted -- wrightwort
  Carlowrightia arizonica A. Gray -- accepted -- Arizona carlowrightia, Arizona wrightwort
  Carlowrightia linearifolia (Torr.) A. Gray -- accepted -- heath wrightwort
  Carlowrightia pubens A. Gray -- not accepted
  Carlowrightia serpyllifolia A. Gray -- accepted -- Trans-Pecos wrightwort
  Carlquistia muirii (A. Gray) B.G. Baldw. -- accepted -- Muir's raillardiopsis
  Carphephorus bellidifolius (Michx.) Torr. & A. Gray -- accepted -- sandywoods chaffhead
  Carphephorus corymbosus (Nutt.) Torr. & A. Gray -- accepted -- coastal plain chaffhead, coastalplain chaffhead
  Carphephorus tomentosus (Michx.) Torr. & A. Gray -- accepted -- woolly chaffhead
  Carphochaete A. Gray -- accepted -- bristlehead
  Carphochaete bigelovii A. Gray -- accepted -- Bigelow bush, Bigelow's bristlehead
  Carum gairdneri (Hook. & Arn.) A. Gray -- not accepted
  Cassandra calyculata var. angustifolia (Aiton) A. Gray -- not accepted
  Cassia bauhinioides A. Gray -- not accepted
  Cassia covesii A. Gray -- not accepted
  Cassia greggii A. Gray -- not accepted
  Cassia pumilio A. Gray -- not accepted
  Cassia wislizeni A. Gray -- not accepted
  Cassia wrightii A. Gray -- not accepted
  Castela emoryi (A. Gray) Moran & Felger -- accepted -- crucifixion thorn, crucifixion-thorn
  Castela erecta ssp. texana (Torr. & A. Gray) Cronquist -- not accepted -- allthorn goatbush, Texan goatbush
  Castela texana (Torr. & A. Gray) Rose -- accepted
  Castilleja attenuata (A. Gray) T.I. Chuang & Heckard -- accepted -- attenuate Indian paintbrush, Indian paintbrush
  Castilleja cinerea A. Gray -- accepted -- ash-gray Indian paintbrush
  Castilleja haydenii (A. Gray) Cockerell -- accepted -- Hayden's Indian paintbrush
  Castilleja integra A. Gray -- accepted -- squawfeather, wholeleaf Indian paintbrush
  Castilleja integra var. integra A. Gray -- accepted -- wholeleaf Indian paintbrush
  Castilleja lanata A. Gray -- accepted -- Sierra woolly Indian paintbrush, Sierran woolly Indian paintbrush, woolly paintbrush
  Castilleja lanata ssp. lanata A. Gray -- accepted -- Sierra woolly Indian paintbrush
  Castilleja lasiorhyncha (A. Gray) T.I. Chuang & Heckard -- accepted -- San Bernardino Mountains Indian paintbrush, San Bernardino Mountains orthocarpus
  Castilleja laxa A. Gray -- not accepted
  Castilleja lemmonii A. Gray -- accepted -- Lemmon's Indian paintbrush, Lemmon's paintbrush
  Castilleja linoides A. Gray -- not accepted
  Castilleja mexicana (Hemsl.) A. Gray -- not accepted
  Castilleja mexicana (Hemsl.) A. Gray -- accepted -- Mexican Indian paintbrush
  Castilleja minor (A. Gray) A. Gray -- accepted -- alkali Indian paintbrush, lesser Indian paintbrush
  Castilleja minor ssp. minor (A. Gray) A. Gray -- accepted -- lesser Indian paintbrush, small annual Indian paintbrush, small Indian paintbrush, smallflower paintbrush
  Castilleja oblongifolia A. Gray -- not accepted
  Castilleja pallescens (A. Gray) Greenm. -- accepted -- pale Indian paintbrush, pale paintbrush
  Castilleja pallescens var. pallescens (A. Gray) Greenm. -- accepted -- pale Indian paintbrush
  Castilleja pallida var. septentrionalis (Lindl.) A. Gray -- not accepted
  Castilleja plagiotoma A. Gray -- accepted -- Mojave Indian paintbrush
  Castilleja purpurea var. lindheimeri (A. Gray) Shinners -- accepted -- Lindheimer's Indian paintbrush
  Castilleja stenantha A. Gray -- not accepted
  Castilleja stenantha A. Gray -- not accepted
  Castilleja suksdorfii A. Gray -- accepted -- Suksdorf's Indian paintbrush
  Castilleja viscidula A. Gray -- accepted -- sticky Indian paintbrush, sticky paintbrush
  Catabrosa aquatica var. uniflora A. Gray -- not accepted
  Cayaponia boykinii (Torr. & A. Gray) Cogn. -- not accepted
  Cayaponia grandifolia (Torr. & A. Gray) Small -- not accepted
  Ceanothus americanus var. intermedius (Pursh) Torr. & A. Gray -- not accepted
  Ceanothus americanus var. pitcheri Torr. & A. Gray -- not accepted
  Ceanothus dentatus Torr. & A. Gray -- accepted -- sandscrub ceanothus
  Ceanothus fendleri A. Gray -- accepted -- Fendler's ceanothus
  Ceanothus greggii A. Gray -- accepted -- desert ceanothus
  Ceanothus greggii ssp. greggii A. Gray -- not accepted -- Gregg's ceanothus
  Ceanothus greggii var. greggii A. Gray -- accepted -- desert ceanothus
  Ceanothus herbaceus var. pubescens (Torr. & A. Gray ex S. Watson) Shinners -- not accepted
  Ceanothus incanus Torr. & A. Gray -- accepted -- coast whitethorn
  Ceanothus ovatus var. pubescens Torr. & A. Gray ex S. Watson -- not accepted
  Ceanothus papillosus Torr. & A. Gray -- accepted -- wartleaf ceanothus
  Ceanothus papillosus ssp. papillosus Torr. & A. Gray -- not accepted -- King hybrid ceanothus
  Ceanothus papillosus var. papillosus Torr. & A. Gray -- accepted -- wartleaf ceanothus
  Ceanothus pubescens (Torr. & A. Gray ex S. Watson) Rydb. ex Small -- not accepted
  Ceanothus velutinus var. laevigatus Torr. & A. Gray -- not accepted
  Cedronella micrantha A. Gray -- not accepted
  Celtis occidentalis var. crassifolia (Lam.) A. Gray -- not accepted
  Celtis occidentalis var. pumila (Pursh) A. Gray -- not accepted -- common hackberry
  Centaurium arizonicum (A. Gray) A. Heller -- not accepted -- Arizona centaury
  Centaurium beyrichii (Torr. & A. Gray ex Torr.) B.L. Rob. -- not accepted -- mountain pink, quinineweed, rock centaury
  Centaurium beyrichii var. beyrichii (Torr. & A. Gray ex Torr.) B.L. Rob. -- not accepted -- quinineweed
  Centaurium calycosum var. arizonicum (A. Gray) Tidestr. -- not accepted
  Centaurium calycosum var. nanum (A. Gray) B.L. Rob. -- not accepted
  Centaurium venustum (A. Gray) B.L. Rob. -- not accepted -- charming centaury
  Centaurium venustum ssp. venustum (A. Gray) B.L. Rob. -- not accepted -- charming centaury
  Centromadia fitchii (A. Gray) Greene -- accepted -- Fitch's tarweed
  Centrostegia A. Gray ex Benth. -- accepted
  Centrostegia leptoceras A. Gray -- not accepted
  Centrostegia leptoceris A. Gray -- not accepted
  Centrostegia thurberi A. Gray ex Benth. -- accepted -- red triangles, spring flower
  Cephalanthera austiniae (A. Gray) A. Heller -- accepted -- phantom orchid
  Ceranthera densiflora (Benth.) A. Gray -- not accepted
  Cerastium brachypodum (Engelm. ex A. Gray) B.L. Rob. -- accepted -- bractpod chickweed, mouse-ear chickweed, short-stalk mouse-ear chickweed, shortstalk chickweed
  Cerastium nutans var. brachypodum Engelm. ex A. Gray -- not accepted
  Ceratophyllum demersum var. echinatum (A. Gray) A. Gray -- not accepted
  Ceratophyllum echinatum A. Gray -- accepted -- spineless hornwort
  Ceratophyllum submersum var. echinatum (A. Gray) Wilmot-Dear -- not accepted
  Cercidium floridum Benth. ex A. Gray -- not accepted
  Cercidium texanum A. Gray -- not accepted
  Cercis occidentalis Torr. ex A. Gray -- accepted -- California redbud
  Cercocarpus breviflorus A. Gray -- accepted -- hairy mountain-mahogany
  Cereus californicus Torr. & A. Gray -- not accepted
  Chaenactis alpina (A. Gray) M.E. Jones -- not accepted
  Chaenactis artemisiifolia (Harv. & A. Gray ex A. Gray) A. Gray -- accepted -- white pincushion
  Chaenactis carphoclinia A. Gray -- accepted -- pebble pincushion
  Chaenactis carphoclinia var. attenuata (A. Gray) M.E. Jones -- not accepted
  Chaenactis carphoclinia var. carphoclinia A. Gray -- accepted -- pebble pincushion, Peeble pincushion
  Chaenactis cusickii A. Gray -- accepted -- Cusick's pincushion
  Chaenactis douglasii var. achilleifolia (Hook. & Arn.) A. Gray -- not accepted
  Chaenactis douglasii var. alpina A. Gray -- accepted -- alpine dustymaiden, alpine pincushion
  Chaenactis fremontii A. Gray -- accepted -- Fremont's pincushion, morningbride, pincushion flower
  Chaenactis glabriuscula var. curta (A. Gray) Jeps. -- not accepted
  Chaenactis glabriuscula var. heterocarpha (Torr. & A. Gray ex A. Gray) H.M. Hall -- accepted -- yellow pincushion
  Chaenactis glabriuscula var. megacephala A. Gray -- accepted -- yellow pincushion
  Chaenactis heterocarpha Torr. & A. Gray ex A. Gray -- not accepted
  Chaenactis nevadensis (Kellogg) A. Gray -- accepted -- Nevada dustymaiden, Nevada pincushion
  Chaenactis nevii A. Gray -- accepted -- John Day's pincushion
  Chaenactis parishii A. Gray -- accepted -- Parish's chaenactis
  Chaenactis stevioides var. brachypappa (A. Gray) H.M. Hall -- not accepted
  Chaenactis suffrutescens A. Gray -- accepted -- Shasta chaenactis
  Chaenactis tanacetifolia A. Gray -- not accepted
  Chaenactis xantiana A. Gray -- accepted -- flesh-color pincushion, fleshcolor pincushion, Xantus pincushion
  Chaerophyllum procumbens var. shortii Torr. & A. Gray -- accepted -- Short's spreading chervil
  Chaerophyllum shortii (Torr. & A. Gray) Bush -- not accepted
  Chaetadelpha A. Gray ex S. Watson -- accepted -- skeletonweed
  Chaetadelpha wheeleri A. Gray ex S. Watson -- accepted -- Wheeler's chaetadelpha, Wheeler's skeletonweed
  Chaetadelphia A. Gray ex S. Watson -- not accepted
  Chaetadelphia wheeleri A. Gray ex S. Watson -- not accepted
  Chaetopappa asteroides var. imberbis A. Gray -- not accepted
  Chaetopappa bellidifolia (A. Gray & Engelm.) Shinners -- accepted -- whiteray leastdaisy
  Chaetopappa bellioides (A. Gray) Shinners -- accepted -- manyflower leastdaisy
  Chaetopappa effusa (A. Gray) Shinners -- accepted -- spreading leastdaisy
  Chaetopappa exilis (A. Gray) D.D. Keck -- not accepted
  Chaetopappa imberbis (A. Gray) G.L. Nesom -- accepted -- awnless leastdaisy
  Chaetopappa lyonii (A. Gray) D.D. Keck -- not accepted
  Chaetopappa parryi A. Gray -- accepted -- Parry's leastdaisy
  Chamaecrista greggii (A. Gray) Pollard ex A. Heller -- accepted -- Gregg's sensitive pea
  Chamaecrista serpens var. wrightii (A. Gray) H.S. Irwin & Barneby -- accepted -- shrubby senna, Wright's sensitive pea
  Chamaecrista wrightii (A. Gray) Wooton & Standl. -- not accepted
  Chamaelirium luteum (L.) A. Gray -- accepted -- fairywand
  Chamaesaracha (A. Gray) Benth. -- accepted -- five eyes
  Chamaesaracha coronopus (Dunal) A. Gray -- accepted -- green false nightshade, green-leaf five-eyes, greenleaf five eyes
  Chamaesaracha nana (A. Gray) A. Gray -- not accepted
  Chamaesaracha sordida (Dunal) A. Gray -- accepted -- hairy five eyes
  Chamaesyce albomarginata (Torr. & A. Gray) Small -- not accepted -- rattlesnake weed, whitemargin euphorbia, whitemargin sandmat, whitemargin spurge
  Chamaesyce celastroides var. lorifolia (A. Gray ex H. Mann) O. Deg. & I. Deg. -- not accepted -- `ekoko
  Chamaesyce fendleri (Torr. & A. Gray) Small -- not accepted -- Fendler's sandmat
  Chamaesyce fendleri var. fendleri (Torr. & A. Gray) Small -- not accepted -- Fendler's sandmat
  Chamaesyce humistrata (Engelm. ex A. Gray) Small -- not accepted -- spreading sandmat
  Chamaesyce lorifolia (A. Gray ex H. Mann) Croizat & O. Deg. -- not accepted
  Chamaesyce melanadenia (Torr. & A. Gray) Millsp. -- not accepted -- prostrate spurge, red-gland spurge, squaw sandmat
  Chamaesyce remyi (A. Gray ex Boiss.) Croizat & O. Deg. -- not accepted -- Remy's sandmat
  Chamaesyce remyi var. remyi (A. Gray ex Boiss.) Croizat & O. Deg. -- not accepted -- akoko, Remy's sandmat
  Chapmannia Torr. & A. Gray -- accepted
  Chapmannia floridana Torr. & A. Gray -- accepted -- Florida alicia
  Chenopodium ambrosioides var. anthelminticum (L.) A. Gray -- not accepted
  Chiogenes hispidula (L.) Torr. & A. Gray -- not accepted
  Chloris verticillata var. aristulata Torr. & A. Gray -- not accepted
  Chloropyron maritimum ssp. canescens (A. Gray) Tank & J.M. Egger -- accepted -- Pt. Reyes bird's-beak
  Chloropyron molle (A. Gray) A. Heller -- accepted -- soft bird's-beak
  Chloropyron molle ssp. molle (A. Gray) A. Heller -- accepted -- soft bird's-beak
  Choisya dumosa (Torr.) A. Gray -- accepted -- Mexican orange, starleaf
  Choisya dumosa var. dumosa (Torr.) A. Gray -- accepted -- Mexican orange
  Chorizanthe californica (Benth.) A. Gray -- not accepted
  Chorizanthe corrugata (Torr.) Torr. & A. Gray -- accepted -- wrinkled chorizanthe, wrinkled spineflower
  Chorizanthe leptoceras (A. Gray) S. Watson -- not accepted
  Chorizanthe perfoliata A. Gray -- not accepted
  Chorizanthe polygonoides Torr. & A. Gray -- accepted -- knotweed spineflower
  Chorizanthe polygonoides var. polygonoides Torr. & A. Gray -- accepted -- knotweed spineflower
  Chorizanthe rigida (Torr.) Torr. & A. Gray -- accepted -- devil's spineflower, spiny chorizanthe, turkshead
  Chorizanthe thurberi (A. Gray ex Benth.) S. Watson -- not accepted
  Chorizanthe uniaristata Torr. & A. Gray -- accepted -- oneawn spineflower
  Chorizanthe watsonii Torr. & A. Gray -- accepted -- five-tooth spineflower, fivetooth spineflower, Watson's chorizanthe
  Chromolaena bigelovii (A. Gray) R.M. King & H. Rob. -- accepted -- Bigelow's thoroughwort
  Chrysactinia A. Gray -- accepted -- chrysactinia
  Chrysactinia mexicana A. Gray -- accepted -- damianita
  Chrysogonum virginianum var. dentatum A. Gray -- not accepted
  Chrysopsis bolanderi A. Gray -- not accepted
  Chrysopsis breweri A. Gray -- not accepted
  Chrysopsis canescens (DC.) Torr. & A. Gray non DC. -- not accepted
  Chrysopsis canescens var. nana A. Gray -- not accepted
  Chrysopsis graminifolia var. aspera (Shuttlew. ex Small) A. Gray -- not accepted
  Chrysopsis graminifolia var. aspera (Shuttlew. ex Small) A. Gray -- not accepted
  Chrysopsis hispida var. stenophylla A. Gray -- not accepted
  Chrysopsis oligantha Chapm. ex Torr. & A. Gray -- not accepted
  Chrysopsis oregona (Nutt.) A. Gray -- not accepted
  Chrysopsis oregona var. scaberrima A. Gray -- not accepted
  Chrysopsis scabrella Torr. & A. Gray -- accepted -- coastal plain goldenaster, coastalplain goldenaster
  Chrysopsis sessiliflora var. bolanderi (A. Gray) A. Gray -- not accepted
  Chrysopsis sessiliflora var. echioides (Benth.) A. Gray -- not accepted
  Chrysopsis stenophylla (A. Gray) Greene -- not accepted
  Chrysopsis villosa var. bolanderi (A. Gray) A. Gray ex Jeps. -- not accepted
  Chrysopsis villosa var. canescens (DC.) A. Gray -- not accepted
  Chrysopsis villosa var. echioides (Benth.) A. Gray -- not accepted
  Chrysopsis villosa var. hispida (Hook.) A. Gray -- not accepted
  Chrysopsis villosa var. sessiliflora (Nutt.) A. Gray -- not accepted
  Chrysopsis villosa var. stenophylla (A. Gray) A. Gray -- not accepted
  Chrysopsis villosa var. viscida A. Gray -- not accepted
  Chrysopsis viscida (A. Gray) Greene -- not accepted
  Chrysopsis wrightii A. Gray -- not accepted
  Chrysothamnus albidus (M.E. Jones ex A. Gray) Greene -- not accepted -- alkali rabbitbrush, whiteflower rabbitbrush
  Chrysothamnus bolanderi (A. Gray) Greene -- not accepted
  Chrysothamnus greenei (A. Gray) Greene -- accepted -- Greene's rabbitbrush
  Chrysothamnus howardii (Parry ex A. Gray) Greene -- not accepted
  Chrysothamnus nauseosus ssp. bigelovii (A. Gray) H.M. Hall & Clem. -- not accepted
  Chrysothamnus nauseosus ssp. bolanderi (A. Gray) H.M. Hall & Clem. -- not accepted
  Chrysothamnus nauseosus ssp. hololeucus (A. Gray) H.M. Hall & Clem. -- not accepted
  Chrysothamnus nauseosus ssp. latisquameus (A. Gray) H.M. Hall & Clem. -- not accepted
  Chrysothamnus nauseosus ssp. leiospermus (A. Gray) H.M. Hall & Clem. -- not accepted
  Chrysothamnus nauseosus var. bigelovii (A. Gray) H.M. Hall -- not accepted
  Chrysothamnus nauseosus var. glabratus (A. Gray) Cronquist -- not accepted
  Chrysothamnus nauseosus var. hololeucus (A. Gray) H.M. Hall -- not accepted
  Chrysothamnus nauseosus var. latisquameus (A. Gray) H.M. Hall -- not accepted
  Chrysothamnus nauseosus var. leiospermus (A. Gray) H.M. Hall -- not accepted
  Chrysothamnus paniculatus (A. Gray) H.M. Hall -- not accepted
  Chrysothamnus parryi (A. Gray) Greene -- not accepted
  Chrysothamnus parryi ssp. howardii (Parry ex A. Gray) H.M. Hall & Clem. -- not accepted
  Chrysothamnus parryi ssp. nevadensis (A. Gray) H.M. Hall & Clem. -- not accepted
  Chrysothamnus parryi ssp. parryi (A. Gray) Greene -- not accepted -- Parry's rabbitbrush
  Chrysothamnus parryi var. howardii (Parry ex A. Gray) Kittell -- not accepted
  Chrysothamnus parryi var. nevadensis (A. Gray) Kittell -- not accepted
  Chrysothamnus pulchellus (A. Gray) Greene -- not accepted -- southwest rabbitbrush, southwestern rabbitbrush
  Chrysothamnus vaseyi (A. Gray) Greene -- accepted -- Vasey's rabbitbrush
  Chrysothamnus viscidiflorus ssp. stenophyllus (A. Gray) H.M. Hall & Clem. -- not accepted
  Chrysothamnus viscidiflorus ssp. viscidiflorus var. stenophyllus (A. Gray) H.M. Hall -- not accepted -- small rabbitbrush, yellow rabbitbrush
  Chrysothamnus viscidiflorus var. stenophyllus (A. Gray) H.M. Hall -- not accepted -- yellow rabbitbrush
  Chylismia (Nutt. ex Torr. & A. Gray) Raim. -- accepted
  Chylismia brevipes (A. Gray) Small -- accepted -- yellow cups
  Chylismia brevipes ssp. brevipes (A. Gray) Small -- accepted -- golden suncup
  Chylismia scapoidea (Torr. & A. Gray) Small -- not accepted -- Paiute suncup
  Chylismia scapoidea (Torr. & A. Gray) Nutt. ex Raim. -- accepted
  Chylismia scapoidea ssp. scapoidea (Torr. & A. Gray) Nutt. ex Raim. -- accepted
  Chylismia scapoidea ssp. scapoidea (Torr. & A. Gray) Small -- not accepted -- Paiute suncup
  Cicuta maculata var. californica (A. Gray) B. Boivin -- not accepted
  Cienfuegosia drummondii (A. Gray) Lewton -- accepted -- yellow flymallow
  Cimicifuga cordifolia (DC.) Torr. & A. Gray -- not accepted
  Cimicifuga racemosa var. cordifolia (DC.) A. Gray -- not accepted
  Cimicifuga racemosa var. dissecta A. Gray -- not accepted
  Cinna arundinacea var. pendula (Trin.) A. Gray -- not accepted
  Cirsium acaule var. americanum A. Gray -- not accepted
  Cirsium altissimum var. filipendulum (Engelm.) A. Gray -- not accepted
  Cirsium americanum (A. Gray) K. Schum. -- not accepted
  Cirsium andersonii (A. Gray) Petr. -- accepted -- Anderson's thistle, rose thistle
  Cirsium andrewsii (A. Gray) Jeps. -- accepted -- Franciscan thistle
  Cirsium arizonicum (A. Gray) Petr. -- accepted -- Arizona thistle
  Cirsium arizonicum var. arizonicum (A. Gray) Petr. -- accepted -- Arizona thistle
  Cirsium arizonicum var. rothrockii (A. Gray) D.J. Keil -- accepted -- Rothrock's thistle
  Cirsium breweri (A. Gray) Jeps. -- not accepted
  Cirsium californicum A. Gray -- not accepted
  Cirsium californicum var. californicum A. Gray -- not accepted -- California thistle
  Cirsium clavatum var. americanum (A. Gray) D.J. Keil -- accepted -- crow thistle, fringed thistle, gray thistle, lacy thistle, mountain slope thistle, porcupine thistle, Rocky Mountain fringed thistle
  Cirsium coulteri Harv. & A. Gray -- not accepted
  Cirsium douglasii var. breweri (A. Gray) D.J. Keil & C.E. Turner -- accepted -- Douglas' thistle
  Cirsium drummondii Torr. & A. Gray -- accepted -- dwarf thistle
  Cirsium eatonii (A. Gray) B.L. Rob. -- accepted -- Eaton's thistle, mountaintop thistle
  Cirsium eatonii var. eatonii (A. Gray) B.L. Rob. -- accepted -- Eaton's thistle, mountaintop thistle
  Cirsium eatonii var. eriocephalum (A. Gray) D.J. Keil -- accepted -- alpine thistle, mountain thistle
  Cirsium eriocephalum A. Gray -- not accepted
  Cirsium grahamii A. Gray -- accepted -- Graham's thistle
  Cirsium hallii (A. Gray) M.E. Jones -- not accepted -- Hall's thistle
  Cirsium hookerianum var. eriocephalum (A. Gray) A. Nelson -- not accepted
  Cirsium horridulum var. elliottii Torr. & A. Gray -- not accepted
  Cirsium hydrophilum var. vaseyi (A. Gray) J.T. Howell -- accepted -- Vasey's thistle
  Cirsium lecontei Torr. & A. Gray -- accepted -- Le Conte's thistle
  Cirsium megacephalum (A. Gray) Cockerell -- not accepted
  Cirsium neomexicanum A. Gray -- accepted -- lavender thistle, New Mexico thistle, powderpuff thistle, Utah thistle
  Cirsium neomexicanum var. neomexicanum A. Gray -- not accepted -- New Mexico thistle
  Cirsium occidentale var. californicum (A. Gray) Keil & C. Turner -- accepted -- cobwebby thistle
  Cirsium occidentale var. coulteri (Harv. & A. Gray) Jeps. -- accepted -- Coulter's thistle
  Cirsium ochrocentrum A. Gray -- accepted -- yellowspine thistle
  Cirsium ochrocentrum ssp. ochrocentrum A. Gray -- accepted -- yellowspine thistle
  Cirsium parryi (A. Gray) Petr. -- accepted -- Cloudcroft thistle, Gila thistle, Mogollon thistle, pale thistle, Parry's thistle
  Cirsium parryi ssp. parryi (A. Gray) Petr. -- not accepted -- Parry's thistle
  Cirsium pitcheri (Torr. ex Eaton) Torr. & A. Gray -- accepted -- Pitcher's thistle, sand dune thistle
  Cirsium quercetorum (A. Gray) Jeps. -- accepted -- Alameda County thistle
  Cirsium quercetorum var. quercetorum (A. Gray) Jeps. -- not accepted -- Alameda County thistle
  Cirsium rothrockii (A. Gray) Petr. -- not accepted -- Rothrock's thistle
  Cirsium scariosum var. americanum (A. Gray) D.J. Keil -- accepted -- dinnerplate thistle, sessile thistle, stemless thistle, Tioga thistle
  Cirsium undulatum var. megacephalum (A. Gray) Fernald -- not accepted
  Cirsium vaseyi (A. Gray) Jeps. -- not accepted
  Cirsium wheeleri (A. Gray) Petr. -- accepted -- Wheeler's thistle
  Cirsium wrightii A. Gray -- accepted -- Wright's marsh thistle, Wright's thistle
  Cistanthe parryi (A. Gray) Hershk. -- accepted -- Parry's pussypaws
  Cistanthe parryi var. parryi (A. Gray) Hershk. -- not accepted -- Parry's pussypaws
  Cistanthe tweedyi (A. Gray) Hershk. -- accepted -- Tweedy's pussypaws
  Cistanthe umbellata var. caudicifera (A. Gray) Kartesz & Gandhi -- not accepted -- Mt. Hood pussypaws
  Citharexylum brachyanthum (A. Gray) A. Gray -- accepted -- boxthorn fiddlewood, Mexican fiddlewood
  Clappia A. Gray -- accepted -- clapdaisy
  Clappia A. Gray -- not accepted
  Clappia suaedifolia A. Gray -- accepted -- fleshy clapdaisy
  Clarkia amoena ssp. whitneyi (A. Gray) F.H. Lewis & M.E. Lewis -- accepted -- Whitney's clarkia
  Clarkia breweri (A. Gray) Greene -- accepted -- fairy fans
  Clarkia epilobioides (Nutt. ex Torr. & A. Gray) A. Nelson & J.F. Macbr. -- accepted -- canyon clarkia, canyon fairyfan
  Clarkia xantiana A. Gray -- accepted -- gunsight clarkia
  Clarkia xantiana ssp. xantiana A. Gray -- accepted -- gunsight clarkia
  Claytonia exigua Torr. & A. Gray -- accepted -- serpentine springbeauty
  Claytonia exigua ssp. exigua Torr. & A. Gray -- accepted -- serpentine springbeauty
  Claytonia exigua ssp. glauca (Torr. & A. Gray) John M. Mill. & K.L. Chambers -- accepted -- serpentine springbeauty
  Claytonia heterophylla (Torr. & A. Gray) Swanson -- not accepted -- variableleaf springbeauty
  Claytonia megarhiza (A. Gray) Parry ex S. Watson -- accepted -- alpine springbeauty
  Claytonia megarhiza var. megarhiza (A. Gray) Parry ex S. Watson -- not accepted -- alpine springbeauty
  Claytonia parviflora var. depressa A. Gray -- not accepted
  Claytonia parviflora var. glauca Nutt. ex Torr. & A. Gray -- not accepted
  Claytonia perfoliata var. depressa (A. Gray) Poelln. -- not accepted
  Claytonia rubra ssp. depressa (A. Gray) John M. Mill. & K.L. Chambers -- accepted -- redstem springbeauty
  Claytonia sibirica var. bulbifera A. Gray -- not accepted -- Siberian springbeauty
  Claytonia sibirica var. heterophylla (Torr. & A. Gray) A. Gray -- not accepted
  Claytonia spathulata var. exigua (Torr. & A. Gray) Hook. & Arn. -- not accepted
  Claytonia spathulata var. tenuifolia Torr. & A. Gray -- not accepted
  Clematis baldwinii Torr. & A. Gray -- accepted -- pine hyacinth
  Clematis baldwinii var. baldwinii Torr. & A. Gray -- not accepted -- pine hyacinth
  Clematis columbiana (Nutt.) Torr. & A. Gray -- accepted -- Columbian virgin's-bower, rock clematis
  Clematis columbiana var. columbiana (Nutt.) Torr. & A. Gray -- accepted -- Columbian virginsbower, rock clematis
  Clematis columbiana var. tenuiloba (A. Gray) J.S. Pringle -- accepted -- Columbian virgin's-bower, rock clematis
  Clematis drummondii Torr. & A. Gray -- accepted -- Drummond's clematis, old man's beard
  Clematis pitcheri Torr. & A. Gray -- accepted -- bluebill, Pitcher's clematis, Pitcher's virginsbower
  Clematis pitcheri var. filifera (Benth.) B.L. Rob. ex A. Gray -- not accepted
  Clematis pitcheri var. pitcheri Torr. & A. Gray -- accepted -- bluebill, Pitcher's clematis
  Clematis tenuiloba A. Gray -- not accepted
  Clematis verticillaris var. columbiana (Nutt.) A. Gray -- not accepted
  Clementsia rhodantha (A. Gray) Rose -- not accepted
  Cleome sandwicensis A. Gray -- not accepted
  Cleome sonorae A. Gray -- not accepted
  Cleome tenuifolia Leconte ex Torr. & A. Gray (pro. syn.) -- not accepted
  Cleomella oocarpa A. Gray -- not accepted
  Cleomella parviflora A. Gray -- accepted -- slender cleomella, small-flower stinkweed, smallflower cleomella
  Clermontia parviflora Gaudich. ex A. Gray -- accepted -- smallflower clermontia
  Cnicus arizonicus A. Gray -- not accepted
  Cnicus breweri var. vaseyi A. Gray -- not accepted
  Cnicus ochrocentrus (A. Gray) A. Gray -- not accepted
  Cnicus parryi A. Gray -- not accepted
  Cnicus undulatus var. megacephalus A. Gray -- not accepted
  Cnicus wheeleri A. Gray -- not accepted
  Cnidoscolus stimulosus (Michx.) Engelm. & A. Gray -- not accepted -- finger rot
  Coelophragmus auriculatus (A. Gray) O.E. Schulz -- accepted -- eared hedgemustard
  Coelostylis Torr. & A. Gray -- not accepted
  Coelostylis loganioides Torr. & A. Gray ex Endl. & Fenzl -- not accepted
  Cogswellia daucifolia (Torr. & A. Gray) M.E. Jones -- not accepted
  Cogswellia macrocarpa (Nutt. ex Torr. & A. Gray) M.E. Jones -- not accepted
  Coldenia greggii (Torr. & A. Gray) A. Gray -- not accepted
  Coldenia hispidissima (Torr. & A. Gray) A. Gray -- not accepted
  Coldenia palmeri A. Gray -- not accepted
  Collinsia childii Parry ex A. Gray -- accepted -- Child's blue eyed Mary
  Collinsia grandiflora var. pusilla A. Gray -- not accepted
  Collinsia greenei A. Gray -- accepted -- Greene's blue eyed Mary
  Collinsia linearis A. Gray -- accepted -- narrowleaf blue eyed Mary
  Collinsia parryi A. Gray -- accepted -- Parry's blue eyed Mary
  Collinsia rattanii A. Gray -- accepted -- sticky blue eyed Mary
  Collinsia rattanii ssp. rattanii A. Gray -- accepted -- sticky blue eyed Mary
  Collinsia rattanii var. linearis (A. Gray) Newsom -- not accepted
  Collinsia torreyi A. Gray -- accepted -- Torrey's blue eyed Mary, Torrey's blue-eyed Mary
  Collinsia torreyi var. torreyi A. Gray -- accepted -- Torrey's blue eyed Mary, Torrey's blue-eyed Mary
  Collinsonia canadensis var. punctata (Elliott) A. Gray -- not accepted
  Collomia debilis var. larsenii (A. Gray) Brand -- not accepted
  Collomia larsenii (A. Gray) Payson -- accepted -- talus collomia
  Collomia tenella A. Gray -- accepted -- diffuse collomia
  Cologania lemmonii A. Gray -- not accepted -- Lemmon's cologania
  Cologania longifolia A. Gray -- not accepted
  Colubrina texensis (Torr. & A. Gray) A. Gray -- accepted -- Texan hogplum, Texas colubrina
  Colubrina texensis var. texensis (Torr. & A. Gray) A. Gray -- accepted -- Texan hogplum
  Columbiadoria hallii (A. Gray) G.L. Nesom -- accepted -- Hall's columbiadoria
  Comarobatia lasiococca (A. Gray) Greene -- not accepted
  Condalia ericoides (A. Gray) M.C. Johnst. -- accepted -- javelina bush
  Condalia lycioides (A. Gray) Weberb. -- not accepted
  Condalia lycioides var. canescens (A. Gray) Trel. -- not accepted
  Condalia obtusifolia (Hook. ex Torr. & A. Gray) Weberb. -- not accepted
  Condalia spathulata A. Gray -- accepted -- knifeleaf condalia, knifeleaf snakewood, squawbush
  Condaliopsis lycioides (A. Gray) Suess. -- not accepted
  Condaliopsis lycioides var. canescens (A. Gray) Suess. -- not accepted
  Conioselinum scopulorum (A. Gray) J.M. Coult. & Rose -- accepted -- Rocky Mountain hemlock-parsley, Rocky Mountain hemlockparsley
  Conoclinium betonicifolium var. integrifolium (A. Gray) T.F. Patterson -- accepted
  Conoclinium dissectum A. Gray -- accepted -- palmleaf thoroughwort
  Conoclinium greggii (A. Gray) Small -- not accepted -- palmleaf thoroughwort
  Conopholis alpina var. mexicana (A. Gray ex S. Watson) R.R. Haynes -- accepted -- alpine squawroot, Mexican cancer-root, Mexican squawroot
  Conopholis mexicana A. Gray ex S. Watson -- not accepted
  Conradina A. Gray -- accepted -- false rosemary
  Conradina canescens (Torr. & A. Gray ex Benth.) A. Gray -- accepted -- false rosemary
  Constancea nevinii (A. Gray) B.G. Baldw. -- accepted -- Nevin's woolly sunflower
  Convolvulus fulcratus (A. Gray) Greene -- not accepted
  Convolvulus hermannioides A. Gray -- not accepted
  Convolvulus luteolus var. fulcratus A. Gray -- not accepted
  Convolvulus occidentalis A. Gray -- not accepted
  Convolvulus sepium var. pubescens (A. Gray) Fernald -- not accepted
  Convolvulus sepium var. repens (L.) A. Gray -- not accepted
  Convolvulus spithamaeus var. pubescens (A. Gray) Fernald -- not accepted
  Conyza canadensis var. glabrata (A. Gray) Cronquist -- not accepted -- Canadian horseweed
  Conyza coulteri A. Gray -- not accepted
  Conyza coulteri var. tenuisecta A. Gray -- not accepted
  Conyza coulteri var. virgata (Benth.) A. Gray -- not accepted
  Conyza eriophylla (A. Gray) Cronquist -- not accepted
  Coprosma ernodeoides A. Gray -- accepted -- `aiakanene
  Coprosma foliosa A. Gray -- accepted -- forest mirrorplant
  Coprosma kauensis (A. Gray) A. Heller -- accepted -- koi
  Coprosma longifolia A. Gray -- accepted -- Oahu mirrorplant
  Coprosma menziesii A. Gray -- accepted -- hupilo
  Coprosma pubens A. Gray -- accepted -- pubescent mirrorplant
  Coprosma rhynchocarpa A. Gray -- accepted -- woodland mirrorplant
  Coptis laciniata A. Gray -- accepted -- Oregon goldthread
  Coptis occidentalis (Nutt.) Torr. & A. Gray -- accepted -- Idaho goldthread
  Corchorus hirtus var. glabellus A. Gray -- not accepted -- Orinoco jute
  Cordylanthus bolanderi (A. Gray) Pennell -- not accepted
  Cordylanthus canescens A. Gray -- not accepted
  Cordylanthus laxiflorus A. Gray -- accepted -- nodding bird's beak, nodding bird's-beak
  Cordylanthus maritimus ssp. canescens (A. Gray) T.I. Chuang & Heckard -- not accepted -- saltmarsh bird's-beak, saltmarsh bird'sbeak
  Cordylanthus maritimus var. canescens (A. Gray) Jeps. -- not accepted
  Cordylanthus mollis A. Gray -- not accepted -- soft bird's-beak
  Cordylanthus mollis ssp. mollis A. Gray -- not accepted -- soft bird's-beak
  Cordylanthus nevinii A. Gray -- accepted -- Nevin's bird's-beak
  Cordylanthus orcuttianus A. Gray -- not accepted -- Orcutt's bird's-beak
  Cordylanthus pilosus A. Gray -- accepted -- hairy bird's-beak
  Cordylanthus pilosus ssp. bolanderi (A. Gray) Munz -- not accepted
  Cordylanthus pilosus ssp. pilosus A. Gray -- accepted -- hairy bird's beak
  Cordylanthus pringlei A. Gray -- accepted -- Pringle's bird's beak
  Cordylanthus rigidus ssp. brevibracteatus (A. Gray) Munz -- accepted -- stiffbranch bird's beak
  Cordylanthus tenuis A. Gray -- accepted -- slender bird's beak, slender bird'sbeak
  Cordylanthus tenuis ssp. tenuis A. Gray -- accepted -- slender bird's beak, slender bird'sbeak
  Cordylanthus wrightii A. Gray -- accepted -- Wright's bird's beak, Wright's bird's-beak
  Cordylanthus wrightii ssp. wrightii A. Gray -- accepted -- Wright's bird's beak, Wright's bird's-beak
  Coreocarpus arizonicus (A. Gray) S.F. Blake -- accepted -- Arizona coreocarpus, little lemonhead
  Coreopsis basalis var. wrightii (A. Gray) S.F. Blake -- not accepted
  Coreopsis bigelovii (A. Gray) H.M. Hall -- accepted -- Bigelow's tickseed
  Coreopsis californica var. newberryi (A. Gray) E.B. Sm. -- not accepted -- Newberry's tickseed
  Coreopsis calliopsidea (DC.) A. Gray -- accepted -- leafstem tickseed
  Coreopsis cardaminefolia (DC.) Torr. & A. Gray -- not accepted
  Coreopsis drummondii (D. Don) Torr. & A. Gray -- not accepted
  Coreopsis drummondii var. wrightii A. Gray -- not accepted
  Coreopsis grandiflora var. harveyana (A. Gray) Sherff -- not accepted -- largeflower tickseed
  Coreopsis grandiflora var. longipes (Hook.) Torr. & A. Gray -- not accepted -- largeflower tickseed
  Coreopsis leavenworthii Torr. & A. Gray -- accepted -- Leavenworth's tickseed
  Coreopsis leavenworthii var. garberi A. Gray -- not accepted
  Coreopsis newberryi A. Gray -- not accepted
  Coreopsis pubescens var. robusta A. Gray ex Eames -- not accepted -- star tickseed
  Coreopsis stillmanii (A. Gray) S.F. Blake -- accepted -- Stillman's tickseed
  Coreopsis wrightii (A. Gray) H.M. Parker -- not accepted -- rock tickseed
  Corethrogyne filaginifolia var. rigida A. Gray -- not accepted
  Corethrogyne filaginifolia var. virgata (Benth.) A. Gray -- not accepted -- common sandaster
  Corethrogyne tomentella (Hook. & Arn.) Torr. & A. Gray -- not accepted
  Coriflora baldwinii (Torr. & A. Gray) W.A. Weber -- not accepted
  Coriflora pitcheri (Torr. & A. Gray) W.A. Weber -- not accepted
  Cornus alba var. occidentalis (Torr. & A. Gray) B. Boivin -- not accepted
  Cornus occidentalis (Torr. & A. Gray) Coville -- not accepted
  Cornus sericea ssp. occidentalis (Torr. & A. Gray) Fosberg -- accepted -- western dogwood
  Cornus stolonifera var. occidentalis (Torr. & A. Gray) C.L. Hitchc. -- not accepted
  Corydalis aurea ssp. occidentalis (Engelm. ex A. Gray) G.B. Ownbey -- accepted -- curvepod fumewort, scrambled eggs
  Corydalis aurea var. micrantha Engelm. ex A. Gray -- not accepted
  Corydalis aurea var. occidentalis Engelm. ex A. Gray -- not accepted
  Corydalis caseana A. Gray -- accepted -- Sierra fumewort
  Corydalis caseana ssp. caseana A. Gray -- accepted -- Sierra fumewort
  Corydalis curvisiliqua ssp. occidentalis (Engelm. ex A. Gray) W.A. Weber -- not accepted -- curvepod fumewort
  Corydalis micrantha (Engelm. ex A. Gray) A. Gray -- accepted -- smallflower corydalis, smallflower fumewort
  Corydalis micrantha ssp. micrantha (Engelm. ex A. Gray) A. Gray -- accepted -- smallflower fumewort
  Cottsia gracilis (A. Gray) W.R. Anderson & C. Davis -- accepted
  Cotyledon strictiflora (A. Gray) Baker -- not accepted
  Coursetia caribaea var. sericea (A. Gray) Lavin -- accepted -- anil falso
  Coursetia glabella (A. Gray) Lavin -- accepted -- smooth babybonnets, smooth coursetia
  Coursetia glandulosa A. Gray -- accepted -- rosary babybonnets
  Coursetia microphylla A. Gray -- not accepted
  Cowania ericifolia Torr. ex A. Gray -- not accepted
  Cracca edwardsii A. Gray -- not accepted
  Cracca edwardsii var. glabella A. Gray -- not accepted
  Cracca edwardsii var. sericea A. Gray -- not accepted
  Cracca glabella (A. Gray) Lavin -- not accepted
  Cracca leiocarpa (A. Gray) Kuntze -- not accepted
  Cracca sericea (A. Gray) A. Gray -- not accepted
  Crassula drummondii (Torr. & A. Gray) Fedde -- accepted -- small-leaf pygmyweed, smallleaf pygmyweed
  Crassula drummondii sensu (Torr. & A. Gray) Fedde -- not accepted -- smallleaf pygmyweed
  Crataegus aestivalis (Walter) Torr. & A. Gray -- accepted -- may hawthorn
  Crataegus berberifolia Torr. & A. Gray -- accepted -- barberry hawthorn, barberry-leaved hawthorn
  Crataegus berberifolia var. berberifolia Torr. & A. Gray -- accepted -- barberry hawthorn
  Crataegus mollis (Torr. & A. Gray) Scheele -- accepted -- Arnold hawthorn, downy hawthorn, red hawthorn
  Crataegus mollis var. mollis (Torr. & A. Gray) Scheele -- accepted -- downy hawthorn
  Crataegus nudiflora Nutt. ex Torr. & A. Gray -- not accepted
  Crepis glauca (Nutt.) Torr. & A. Gray -- not accepted
  Crepis intermedia A. Gray -- accepted -- gray hawksbeard, limestone hawksbeard
  Crepis occidentalis ssp. costata (A. Gray) Babc. & Stebbins -- accepted -- largeflower hawksbeard
  Crepis occidentalis var. costata A. Gray -- not accepted
  Crepis pleurocarpa A. Gray -- accepted -- nakedstem hawksbeard
  Crepis runcinata (James) Torr. & A. Gray -- accepted -- dandelion hawksbeard, fiddle-leaf hawk's-beard, fiddle-leaf hawksbeard, fiddleleaf hawksbeard
  Crepis runcinata ssp. andersonii (A. Gray) Babc. & Stebbins -- accepted -- Anderson's hawksbeard
  Crepis runcinata ssp. runcinata (James) Torr. & A. Gray -- accepted -- dandelion hawksbeard, fiddle-leaf hawk's-beard, fiddleleaf hawksbeard
  Crepis runcinata var. andersonii (A. Gray) Cronquist -- not accepted
  Cristatella jamesii Torr. & A. Gray -- not accepted
  Crockeria chrysantha Greene ex A. Gray -- not accepted
  Crookea microsepala (Torr. & A. Gray) Small -- not accepted
  Croptilon divaricatum var. hookerianum (Torr. & A. Gray) Shinners -- not accepted
  Croptilon hookerianum (Torr. & A. Gray) House -- accepted -- Hooker's scratchdaisy
  Croptilon hookerianum var. hookerianum (Torr. & A. Gray) House -- accepted -- Hooker's scratchdaisy
  Croton capitatus var. lindheimeri (Engelm. & A. Gray) Müll. Arg. -- not accepted -- Lindheimer's hogwort
  Croton eutrigynus A. Gray -- not accepted
  Croton lindheimeri (Engelm. & A. Gray) Alph. Wood -- accepted -- Lindheimer's hogwort
  Crusea subulata (DC.) A. Gray -- not accepted
  Crusea tricocca (Torr. & A. Gray) A. Heller -- not accepted
  Crusea wrightii A. Gray -- not accepted
  Cryptantha affinis (A. Gray) Greene -- accepted -- common cryptantha, quill cryptantha
  Cryptantha ambigua (A. Gray) Greene -- accepted -- basin cryptantha, Wickes cryptantha, Wilkes cryptantha
  Cryptantha barbigera (A. Gray) Greene -- accepted -- bearded catseye, bearded cryptantha
  Cryptantha calycosa (A. Gray) Rydb. -- not accepted
  Cryptantha crassisepala (Torr. & A. Gray) Greene -- accepted -- deertongue, thick-sepal catseye, thicksepal cryptantha
  Cryptantha crassisepala var. crassisepala (Torr. & A. Gray) Greene -- accepted -- thicksepal catseye, thicksepal cryptantha
  Cryptantha dumetorum (Greene ex A. Gray) Greene -- accepted -- bush-loving catseye, bushloving cryptantha
  Cryptantha fendleri (A. Gray) Greene -- accepted -- Fendler's cryptantha, sanddune catseye, sanddune cryptantha
  Cryptantha holoptera (A. Gray) J.F. Macbr. -- accepted -- winged catseye, winged cryptantha
  Cryptantha humilis (A. Gray) Payson -- accepted -- round-spike catseye, roundspike cryptantha
  Cryptantha intermedia (A. Gray) Greene -- accepted -- Clearwater catseye, Clearwater cryptantha, common cryptantha
  Cryptantha intermedia var. intermedia (A. Gray) Greene -- not accepted -- Clearwater catseye
  Cryptantha micrantha ssp. lepida (A. Gray) Mathew & P.H. Raven -- not accepted
  Cryptantha micrantha var. lepida (A. Gray) I.M. Johnst. -- accepted -- redroot cryptantha
  Cryptantha micromeres (A. Gray) Greene -- accepted -- pygmyflower cryptantha
  Cryptantha microstachys (Greene ex A. Gray) Greene -- accepted -- Tejon cryptantha
  Cryptantha muricata var. jonesii (A. Gray) I.M. Johnst. -- not accepted -- Jones' catseye, Jones' cryptantha
  Cryptantha oxygona (A. Gray) Greene -- accepted -- sharpnut cryptantha, sharpseed cryptantha
  Cryptantha palmeri (A. Gray) Payson -- accepted -- Palmer's catseye, Palmer's cryptantha
  Cryptantha pattersonii (A. Gray) Greene -- not accepted
  Cryptantha pusilla (Torr. & A. Gray) Greene -- accepted -- low catseye, low cryptantha
  Cryptantha sericea (A. Gray) Payson -- accepted -- silky cryptantha
  Cryptantha setosissima (A. Gray) Payson -- accepted -- bristly catseye, bristly cryptantha
  Cryptantha torreyana (A. Gray) Greene -- accepted -- Torrey's cat's-eye, Torrey's cryptantha
  Cryptantha torreyana var. calycosa (A. Gray) Greene -- not accepted
  Cryptantha torreyana var. torreyana (A. Gray) Greene -- not accepted -- Torrey's catseye
  Cryptantha utahensis (A. Gray) Greene -- accepted -- scented catseye, scented cryptantha, Utah cryptantha
  Cryptantha watsonii (A. Gray) Greene -- accepted -- Watson's cryptantha
  Cucurbita digitata A. Gray -- accepted -- fingerleaf gourd
  Cuphea wrightii A. Gray -- accepted -- Wright's waxweed
  Cuscuta rostrata Shuttlw. ex Engelm. & A. Gray -- accepted -- beaked dodder
  Cusickiella douglasii (A. Gray) Rollins -- accepted -- alkali cusickiella, alkali false whitlowgrass
  Cyanea coriacea (A. Gray) Hillebr. -- accepted -- leatherleaf cyanea
  Cyanea leptostegia A. Gray -- accepted -- giant koke'e cyanea, giant kokee cyanea
  Cyanea obtusa (A. Gray) Hillebr. -- accepted -- bluntlobe cyanea
  Cyanea pilosa A. Gray -- accepted -- hairy cyanea
  Cyanea pilosa ssp. pilosa A. Gray -- accepted -- hairy cyanea
  Cyanea platyphylla (A. Gray) Hillebr. -- accepted -- haha, puna cyanea
  Cyanea superba (Cham.) A. Gray -- accepted -- Mt. Kaala cyanea
  Cyanea superba ssp. superba (Cham.) A. Gray -- accepted -- Mt. Kaala cyanea
  Cyanea tritomantha A. Gray -- accepted -- `aku, `aku `aku
  Cyanococcus atrococcus (A. Gray) Small -- not accepted
  Cycladenia humilis var. tomentosa (A. Gray) A. Gray -- not accepted
  Cyclanthera dissecta (Torr. & A. Gray) Arn. -- accepted -- cut-leaf cyclanthera, cutleaf cyclanthera
  Cylindropuntia californica (Torr. & A. Gray) F.M. Knuth -- accepted
  Cylindropuntia californica var. californica (Torr. & A. Gray) F.M. Knuth -- accepted
  Cymanchum blodgettii (A. Gray) Shinners -- not accepted
  Cymopterus acaulis var. fendleri (A. Gray) Goodrich -- not accepted -- Fendler spring parsley, Fendler's springparsley
  Cymopterus alpinus A. Gray -- not accepted
  Cymopterus anisatus A. Gray -- not accepted
  Cymopterus cinerarius A. Gray -- accepted -- gray springparsley
  Cymopterus fendleri A. Gray -- not accepted
  Cymopterus glomeratus var. fendleri (A. Gray) R.L. Hartm. -- not accepted -- Fendler's springparsley
  Cymopterus littoralis auct. non A. Gray -- not accepted
  Cymopterus montanus Nutt. ex Torr. & A. Gray -- accepted -- Montana wavewing, mountain springparsley
  Cymopterus purpurascens (A. Gray) M.E. Jones -- accepted -- Utah springparsley, widewing spring parsley, widewing springparsley
  Cymopterus terebinthinus (Hook.) Torr. & A. Gray -- not accepted
  Cymopterus terebinthinus var. albiflorus (Torr. & A. Gray) M.E. Jones -- not accepted
  Cymopterus terebinthinus var. foeniculaceus (Nutt. ex Torr. & A. Gray) Cronquist -- not accepted
  Cynanchum arizonicum (A. Gray) Shinners -- not accepted -- Arizona swallow-wort, Arizona swallowwort
  Cynanchum blodgettii (A. Gray) Shinners -- not accepted -- Blodgett's swallow-wort
  Cynanchum pringlei (A. Gray) Henrickson -- not accepted -- Pringle's swallow-wort, Pringle's swallowwort
  Cynoctonum angustifolium (Torr. & A. Gray) Small -- not accepted
  Cynoctonum sessilifolium var. angustifolium Torr. & A. Gray -- not accepted
  Cynoglossum occidentale A. Gray -- accepted -- western hound's tongue
  Cynomarathrum nuttallii (A. Gray) J.M. Coult. & Rose -- not accepted
  Cypripedium californicum A. Gray -- accepted -- California lady's slipper
  Cyrtandra acutangula Seem. ex A. Gray -- not accepted
  Cyrtandra anthropophagorum Seem. ex A. Gray -- accepted
  Cyrtandra arguta (A. Gray) C.B. Clarke -- not accepted
  Cyrtandra ciliata Seem. ex A. Gray -- not accepted
  Cyrtandra coleoides Seem. ex A. Gray -- not accepted
  Cyrtandra dolichocarpa A. Gray -- accepted
  Cyrtandra induta A. Gray -- accepted
  Cyrtandra involucrata Seem. ex A. Gray -- not accepted
  Cyrtandra labiosa A. Gray -- accepted
  Cyrtandra lysiosepala (A. Gray) Hillebr. -- not accepted
  Cyrtandra lysiosepala (A. Gray) C.B. Clarke -- accepted -- oppositeleaf cyrtandra
  Cyrtandra lysiosepala var. lysiosepala (A. Gray) C.B. Clarke -- not accepted
  Cyrtandra macraei A. Gray -- accepted -- upland cyrtandra
  Cyrtandra milnei Seem. ex A. Gray -- accepted
  Cyrtandra pickeringii A. Gray -- accepted -- Pickering's cyrtandra
  Cyrtandra platyphylla A. Gray -- accepted -- `ilihia
  Cyrtandra pogonantha A. Gray -- accepted
  Cyrtandra pritchardii Seem. ex A. Gray -- not accepted
  Cyrtandra pulchella Rich ex A. Gray -- accepted
  Cyrtandra richii A. Gray -- accepted
  Cyrtandra samoensis A. Gray -- accepted
  Cyrtandra taitensis Rich ex A. Gray -- accepted
  Cyrtandra triflora var. gaudichaudii A. Gray -- not accepted
  Cyrtandra triflora var. lysiosepala A. Gray -- not accepted
  Cyrtandra vitiensis Seem. ex A. Gray -- not accepted
  Dalea albiflora A. Gray -- accepted -- white flower dalea, whiteflower prairie clover, whiteflower prairieclover
  Dalea arborescens Torr. ex A. Gray -- not accepted
  Dalea argyrea A. Gray -- not accepted
  Dalea bicolor var. argyrea (A. Gray) Barneby -- accepted -- silver prairie clover, silver prairieclover
  Dalea brachystachya A. Gray -- not accepted -- Fort Bowie prairie clover, Fort Bowie prairie-clover
  Dalea brachystachys A. Gray -- accepted -- Fort Bowie prairie clover, Fort Bowie prairie-clover, Fort Bowie prairieclover
  Dalea calycosa A. Gray -- not accepted
  Dalea carnea var. albida (Torr. & A. Gray) Barneby -- accepted -- whitetassels
  Dalea compacta var. pubescens (A. Gray) Barneby -- accepted -- compact prairie clover, compact prairieclover
  Dalea emarginata (Torr. & A. Gray) Shinners -- accepted -- wedgeleaf prairie clover, wedgeleaf prairieclover
  Dalea emoryi A. Gray -- not accepted
  Dalea filiformis A. Gray -- accepted -- Sonoran prairie clover, Sonoran prairie-clover, Sonoran prairieclover
  Dalea foliosa (A. Gray) Barneby -- accepted -- leafy prairie clover, leafy prairie-clover
  Dalea fremontii Torr. ex A. Gray -- not accepted
  Dalea frutescens A. Gray -- accepted -- black dalea, black prairie clover, black prairieclover
  Dalea greggii A. Gray -- accepted -- Gregg's dalea, Gregg's prairie clover, Gregg's prairieclover
  Dalea hallii A. Gray -- accepted -- Hall's prairie clover, Hall's prairieclover
  Dalea jamesii (Torr.) Torr. & A. Gray -- accepted -- James' dalea, James' prairie clover, James' prairieclover
  Dalea lachnostachys A. Gray -- accepted -- gland-leaf prairie-clover, glandleaf prairie clover, glandleaf prairieclover
  Dalea lasiathera A. Gray -- accepted -- purple dalea, purple prairie clover
  Dalea lemmonii Parry ex A. Gray -- not accepted
  Dalea nana Torr. ex A. Gray -- accepted -- dwarf dalea, dwarf prairie clover, dwarf prairie-clover, dwarf prairieclover
  Dalea nana var. elatior A. Gray ex B.L. Turner -- not accepted
  Dalea nana var. nana Torr. ex A. Gray -- accepted -- dwarf prairie clover, dwarf prairieclover
  Dalea neomexicana (A. Gray) Cory -- accepted -- downy prairie clover, downy prairie-clover, downy prairieclover, New Mexico dalea
  Dalea neomexicana var. neomexicana (A. Gray) Cory -- accepted -- downy prairie clover, New Mexican dalea, New Mexican prairieclover
  Dalea obovata (Torr. & A. Gray) Shinners -- accepted -- pussyfoot
  Dalea ordiae A. Gray -- not accepted
  Dalea parryi Torr. & A. Gray -- not accepted
  Dalea phleoides (Torr. & A. Gray) Shinners -- accepted -- slimspike prairie clover, slimspike prairieclover
  Dalea phleoides var. microphylla (Torr. & A. Gray) Barneby -- accepted -- slimspike prairie clover, slimspike prairieclover
  Dalea phleoides var. phleoides (Torr. & A. Gray) Shinners -- accepted -- slimspike prairie clover, slimspike prairieclover
  Dalea pogonathera A. Gray -- accepted -- bearded dalea, bearded prairie clover, bearded prairieclover
  Dalea pogonathera var. pogonathera A. Gray -- accepted -- bearded dalea, bearded prairie clover, bearded prairieclover
  Dalea polygonoides A. Gray -- accepted -- six-weeks prairie-clover, sixweeks prairie clover, sixweeks prairieclover
  Dalea pringlei A. Gray -- accepted -- Pringle's dalea, Pringle's prairie clover
  Dalea scoparia A. Gray -- not accepted
  Dalea searlsiae (A. Gray) Barneby -- accepted -- Searle's prairieclover, Searles dalea, Searles' prairie clover
  Dalea spinosa A. Gray -- not accepted
  Dalea tenuifolia (A. Gray) Shinners -- accepted -- bigtop dalea, Flimleaf prairieclover, slimleaf prairie clover, slimleaf prairieclover
  Dalea thyrsiflora A. Gray -- not accepted
  Dalea versicolor ssp. versicolor var. sessilis (A. Gray) Barneby -- not accepted -- oakwoods dalea, oakwoods prairie clover
  Dalea versicolor var. sessilis (A. Gray) Barneby -- accepted -- oakwoods prairie clover
  Dalea villosa var. grisea (Torr. & A. Gray) Barneby -- accepted -- silky prairie clover, silky prairieclover
  Dalea wislizeni ssp. sessilis (A. Gray) Gentry -- not accepted
  Dalea wislizeni var. sessilis A. Gray -- not accepted
  Dalea wrightii A. Gray -- accepted -- Wright's dalea, Wright's prairie clover, Wright's prairie-clover, Wright's prairieclover
  Daucosma Engelm. & A. Gray ex A. Gray -- accepted
  Daucosma laciniata Engelm. & A. Gray -- accepted -- meadow parasol
  Decachaena nana (A. Gray) Small -- not accepted
  Decachaena tomentosa (A. Gray) Small -- not accepted
  Decodon verticillatus var. laevigatus Torr. & A. Gray -- not accepted
  Deinandra floribunda (A. Gray) Davidson & Moxley -- accepted -- Tecate tarweed
  Deinandra paniculata (A. Gray) Davidson & Moxley -- accepted -- grassland tarweed, San Diego tarweed
  Delphinium andersoni A. Gray -- not accepted
  Delphinium andersoni var. andersoni A. Gray -- not accepted
  Delphinium andersonii A. Gray -- accepted -- Anderson's larkspur
  Delphinium andersonii ssp. andersonii A. Gray -- not accepted -- Anderson's larkspur
  Delphinium californicum Torr. & A. Gray -- accepted -- California larkspur
  Delphinium californicum ssp. californicum Torr. & A. Gray -- accepted -- California larkspur
  Delphinium decorum var. patens (Benth.) A. Gray -- not accepted
  Delphinium hesperium A. Gray -- accepted -- foothill larkspur
  Delphinium hesperium ssp. hesperium A. Gray -- accepted -- foothill larkspur
  Delphinium nudicaule Torr. & A. Gray -- accepted -- red larkspur
  Delphinium nuttallii A. Gray -- accepted -- upland larkspur
  Delphinium nuttallii ssp. nuttallii A. Gray -- accepted -- upland larkspur
  Delphinium parishii A. Gray -- accepted -- desert larkspur
  Delphinium parishii ssp. parishii A. Gray -- accepted -- Parish's desert larkspur, Parish's larkspur
  Delphinium parryi A. Gray -- accepted -- San Bernardino larkspur
  Delphinium parryi ssp. parryi A. Gray -- accepted -- San Bernardino larkspur
  Delphinium scopulorum A. Gray -- accepted -- Rocky Mountain larkspur
  Delphinium scopulorum auct. non A. Gray -- not accepted -- Rocky Mountain larkspur
  Delphinium scopulorum var. glaucum (S. Watson) A. Gray -- not accepted
  Delphinium scopulorum var. stachydeum A. Gray -- not accepted
  Delphinium stachydeum (A. Gray) Tidestr. -- accepted -- spiked larkspur
  Delphinium trolliifolium A. Gray -- accepted -- Columbian larkspur
  Delphinium variegatum Torr. & A. Gray -- accepted -- royal larkspur
  Delphinium variegatum ssp. variegatum Torr. & A. Gray -- accepted -- royal larkspur
  Descurainia californica (A. Gray) O.E. Schulz -- accepted -- Sierra tansymustard, Sierran tansy mustard, Sierran tansymustard
  Descurainia incana ssp. incisa (Engelm. ex A. Gray) Kartesz & Gandhi -- not accepted -- mountain tansy mustard, mountain tansymustard
  Descurainia incisa (Engelm. ex A. Gray) Britton -- accepted -- mountain tansymustard
  Descurainia incisa ssp. filipes (A. Gray) Rollins -- not accepted
  Descurainia incisa ssp. incisa (Engelm. ex A. Gray) Britton -- accepted -- mountain tansymustard
  Descurainia incisa var. incisa (Engelm. ex A. Gray) Britton -- not accepted
  Descurainia pinnata ssp. filipes (A. Gray) Detling -- not accepted -- western tansy mustard, western tansymustard
  Descurainia pinnata var. filipes (A. Gray) M. Peck -- not accepted
  Descurainia richardsonii ssp. incisa (Engelm. ex A. Gray) Detling -- not accepted
  Desmanthus leptolobus Torr. & A. Gray -- accepted -- prairie bundleflower, slenderlobe bundleflower
  Desmodium angustifolium var. gramineum (A. Gray) B.G. Schub. -- not accepted
  Desmodium annuum A. Gray -- not accepted
  Desmodium batocaulon A. Gray -- accepted -- San Pedro tick trefoil, San Pedro ticktrefoil
  Desmodium bracteosum var. longifolium (Torr. & A. Gray) B.L. Rob. -- not accepted
  Desmodium canescens var. villosissimum Torr. & A. Gray -- not accepted
  Desmodium cinerascens A. Gray -- accepted -- spiked tick trefoil, spiked ticktrefoil
  Desmodium cuspidatum var. longifolium (Torr. & A. Gray) B.G. Schub. -- accepted -- largebract ticktrefoil
  Desmodium grahamii A. Gray -- accepted -- Graham's tick trefoil, Graham's ticktrefoil
  Desmodium gramineum A. Gray -- accepted -- grass-leaf tick trefoil, grassleaf ticktrefoil
  Desmodium illinoense A. Gray -- accepted -- Illinois tickclover, Illinois ticktrefoil
  Desmodium lineatum var. polymorphum A. Gray -- not accepted
  Desmodium longifolium (Torr. & A. Gray) Smyth -- not accepted
  Desmodium neomexicanum A. Gray -- accepted -- New Mexico tickclover, New Mexico ticktrefoil
  Desmodium paniculatum var. angustifolium Torr. & A. Gray -- not accepted
  Desmodium paniculatum var. pubens Torr. & A. Gray -- not accepted
  Desmodium procumbens var. exiguum (A. Gray) B.G. Schub. -- accepted -- western trailing tick trefoil, western trailing ticktrefoil
  Desmodium psilocarpum A. Gray -- accepted -- Santa Cruz Island tick trefoil, Santa Cruz Island ticktrefoil
  Desmodium sessilifolium (Torr.) Torr. & A. Gray -- accepted -- sessile tickclover, sessileleaf tickclover, sessileleaf ticktrefoil
  Desmodium tenuifolium Torr. & A. Gray -- accepted -- slimleaf ticktrefoil
  Desmodium wislizeni Engelm. ex A. Gray -- not accepted
  Desmodium wrightii A. Gray -- not accepted
  Deyeuxia alopecuroides Nutt. ex A. Gray -- not accepted
  Deyeuxia pickeringii (A. Gray) Vasey -- not accepted
  Deyeuxia porteri (A. Gray) Vasey -- not accepted
  Dianthera humilis (Michx.) Engelm. & A. Gray -- not accepted
  Dianthera parviflora (Buckley) A. Gray -- not accepted
  Dianthera parvifolia (Torr.) A. Gray -- not accepted
  Diapedium torreyi (A. Gray) A. Heller -- not accepted
  Diaperia candida (Torr. & A. Gray) Benth. -- accepted -- silver pygmycudweed
  Diaperia drummondii (Torr. & A. Gray) Benth. -- not accepted
  Diaperia verna var. drummondii (Torr. & A. Gray) Morefield -- accepted -- spring pygmycudweed
  Dichaetophora A. Gray -- accepted -- dichaetophora
  Dichaetophora campestris A. Gray -- accepted -- plainsdaisy
  Dichanthelium acuminatum var. villosum (A. Gray) Gould & C.A. Clark -- not accepted
  Dichanthelium xanthophysum (A. Gray) Freckmann -- accepted -- slender rosette grass
  Dichrophyllum bicolor (Engelm. & A. Gray) Klotzsch & Garcke -- not accepted
  Dicliptera brachiata var. attenuata A. Gray -- not accepted
  Dicliptera pseudoverticillaris A. Gray -- not accepted
  Dicliptera torreyi A. Gray -- not accepted
  Dicoria Torr. ex A. Gray -- accepted -- dicoria, twinbugs
  Dicoria brandegeei A. Gray -- not accepted
  Dicoria canescens A. Gray -- accepted -- desert twinbugs
  Dicoria canescens ssp. brandegeei (A. Gray) Kartesz -- not accepted -- Brandegee's twinbugs, desert twinbugs
  Dicoria canescens ssp. canescens A. Gray -- not accepted -- desert twinbugs
  Dicoria canescens var. brandegeei (A. Gray) Cronquist -- not accepted
  Dicranocarpus A. Gray -- accepted -- dicranocarpus
  Dicranocarpus parviflorus A. Gray -- accepted -- pitchfork
  Dicranostegia (A. Gray) Pennell -- accepted
  Dicranostegia orcuttiana (A. Gray) Pennell -- accepted -- Orcutt's bird's-beak
  Didymoglossum petersii (A. Gray) Copel. -- accepted -- dwarf bristle fern
  Dieteria bigelovii (A. Gray) D.R. Morgan & R.L. Hartm. -- accepted
  Dieteria bigelovii var. bigelovii (A. Gray) D.R. Morgan & R.L. Hartm. -- accepted
  Dieteria canescens var. glabra (A. Gray) D.R. Morgan & R.L. Hartm. -- accepted -- hoary tansyaster
  Dieteria canescens var. shastensis (A. Gray) D.R. Morgan & R.L. Hartm. -- accepted
  Dieteria incana (Lindl.) Torr. & A. Gray -- not accepted
  Dimeresia A. Gray -- accepted -- dimeresia
  Dimeresia howellii A. Gray -- accepted -- doublet
  Dimersia A. Gray -- not accepted
  Dimersia howelli A. Gray -- not accepted
  Dioclea multiflora (Torr. & A. Gray) C. Mohr -- accepted -- Boykin's clusterpea
  Diodia teres var. angustata A. Gray -- not accepted -- poor joe, poorjoe
  Diodia tricocca Torr. & A. Gray -- not accepted
  Diodia virginiana var. latifolia Torr. & A. Gray -- accepted -- Virginia buttonweed
  Diphysa thurberi (A. Gray) Rydb. ex Standl. -- accepted -- Thurber's diphysa
  Diplostelma bellioides A. Gray -- not accepted
  Dipteracanthus linearis Torr. & A. Gray -- not accepted
  Dipteracanthus micranthus Engelm. & A. Gray -- not accepted
  Dipteracanthus nudiflorus Engelm. & A. Gray -- not accepted
  Dirca occidentalis A. Gray -- accepted -- western leatherwood
  Ditaxis adenophora auct. non (A. Gray) Pax & K. Hoffm. -- not accepted
  Ditaxis adenophora (A. Gray) Pax & K. Hoffm. -- accepted -- glandular silverbush
  Ditaxis humilis (Engelm. & A. Gray) Pax -- accepted -- low silverbush
  Dodecahema leptoceras (A. Gray) Reveal & Hardham -- accepted -- slender-horned spineflower, slenderhorn spineflower
  Dodecatheon alpinum (A. Gray) Greene -- not accepted -- alpine shootingstar
  Dodecatheon alpinum ssp. alpinum (A. Gray) Greene -- not accepted -- alpine shootingstar
  Dodecatheon hendersonii A. Gray -- not accepted -- mosquito bills
  Dodecatheon hendersonii ssp. hendersonii A. Gray -- not accepted -- mosquito bills
  Dodecatheon pulchellum ssp. macrocarpum (A. Gray) Roy L. Taylor & MacBryde -- not accepted -- darkthroat shootingstar
  Dodecatheon pulchellum var. macrocarpum (A. Gray) Reveal -- not accepted -- darkthroat shootingstar
  Doellingeria umbellata ssp. pubens (A. Gray) Á. Löve & D. Löve -- not accepted
  Doellingeria umbellata var. latifolia (A. Gray) House -- not accepted
  Doellingeria umbellata var. pubens (A. Gray) Britton -- accepted -- parasol whitetop
  Dolicholus latifolius (Nutt. ex Torr. & A. Gray) Vail -- not accepted
  Douglasia laevigata A. Gray -- not accepted -- cliff dwarf-primrose
  Douglasia laevigata var. laevigata A. Gray -- not accepted -- cliff dwarf-primrose
  Douglasia montana A. Gray -- not accepted -- Rocky Mountain dwarf-primrose
  Douglasia nivalis var. dentata (S. Watson) A. Gray -- not accepted -- snow dwarf-primrose
  Downingia bicornuta A. Gray -- accepted -- double-horned downingia, doublehorn calicoflower
  Downingia bicornuta var. bicornuta A. Gray -- accepted -- doublehorn calicoflower
  Downingia elegans var. corymbosa (A. DC.) A. Gray -- not accepted
  Draba brachycarpa Nutt. ex Torr. & A. Gray -- accepted -- short-pod whitlowgrass, shortfruited draba, shortpod draba
  Draba cuneifolia Nutt. ex Torr. & A. Gray -- accepted -- wedgeleaf draba, wedgeleaf whitlowgrass
  Draba cuneifolia var. cuneifolia Nutt. ex Torr. & A. Gray -- accepted -- wedgeleaf draba, wedgeleaf whitlowgrass
  Draba cuneifolia var. platycarpa (Torr. & A. Gray) S. Watson -- not accepted
  Draba douglasii A. Gray -- not accepted
  Draba douglasii var. douglasii A. Gray -- not accepted
  Draba eurycarpa A. Gray -- not accepted
  Draba platycarpa Torr. & A. Gray -- accepted -- broad-pod whitlowgrass, broadpod draba, broadpod whitlowgrass
  Draba streptocarpa A. Gray -- accepted -- pretty draba, pretty whitlowgrass
  Draba ventosa A. Gray -- accepted -- wind draba, Wind River draba
  Draperia systula (A. Gray) Torr. -- not accepted
  Draperia systyla (A. Gray) Torr. -- accepted -- violet draperia
  Drymaria effusa A. Gray -- accepted -- pinewoods drymary
  Drymaria effusa var. effusa A. Gray -- accepted -- pinewoods drymary
  Drymaria sperguloides A. Gray -- not accepted
  Drymaria tenella A. Gray -- not accepted
  Dryopetalon A. Gray -- accepted
  Dryopetalon runcinatum A. Gray -- accepted -- rock-mustard, rockmustard
  Dryopteris cristata (L.) A. Gray -- accepted -- crested woodfern
  Dryopteris dilatata auct. non (Hoffm.) A. Gray -- not accepted
  Dryopteris goldiana (Hook. ex Goldie) A. Gray -- accepted -- Goldie's woodfern
  Dryopteris intermedia (Muhl. ex Willd.) A. Gray -- accepted -- intermediate woodfern
  Dryopteris marginalis (L.) A. Gray -- accepted -- marginal woodfern, woodfern
  Dryopteris noveboracensis (L.) A. Gray -- not accepted
  Dubautia arborea (A. Gray) D.D. Keck -- accepted -- Mauna Kea dubautia
  Dubautia ciliolata var. juniperoides (A. Gray) D.D. Keck -- not accepted
  Dubautia laevigata A. Gray -- accepted -- smooth dubautia
  Dubautia latifolia (A. Gray) D.D. Keck -- accepted -- koholapehu, na`ena`e
  Dubautia menziesii (A. Gray) D.D. Keck -- accepted -- mountain dubautia
  Dubautia paleata A. Gray -- accepted -- na`ena`e pua kea
  Dubautia platyphylla (A. Gray) D.D. Keck -- accepted -- cinderslope dubautia
  Dubautia scabra ssp. leiophylla (A. Gray) G.D. Carr -- accepted -- rough dubautia
  Dubautia scabra var. leiophylla (A. Gray) D.D. Keck -- not accepted
  Dubautia struthioloides (A. Gray) D.D. Keck -- not accepted
  Dugaldia hoopesii (A. Gray) Rydb. -- not accepted
  Dupontia cooleyi A. Gray -- not accepted
  Dyschoriste angusta (A. Gray) Small -- accepted -- pineland snakeherb
  Dyschoriste decumbens (A. Gray) Kuntze -- not accepted -- spreading snakeherb
  Dyschoriste linearis (Torr. & A. Gray) Kuntze -- accepted -- narrowleaf dyschoriste, polkadots
  Dyschoriste linearis var. linearis (Torr. & A. Gray) Kuntze -- accepted -- polkadots
  Dyschoriste oblongifolia var. angusta (A. Gray) R.W. Long -- not accepted
  Dyschoriste schiedeana var. decumbens (A. Gray) Henrickson -- accepted -- spreading snakeherb
  Dysodiopsis (A. Gray) Rydb. -- accepted -- dogfennel
  Dysodiopsis tagetoides (Torr. & A. Gray) Rydb. -- accepted -- false dogfennel, marygold dogweed
  Dyssodia aurea (A. Gray) A. Nelson -- not accepted
  Dyssodia aurea var. polychaeta (A. Gray) M.C. Johnst. -- not accepted
  Dyssodia concinna (A. Gray) B.L. Rob. -- not accepted
  Dyssodia cooperi A. Gray -- not accepted
  Dyssodia hartwegii (A. Gray) B.L. Rob. -- not accepted
  Dyssodia neomexicana (A. Gray) B.L. Rob. -- not accepted
  Dyssodia pentachaeta ssp. hartwegii (A. Gray) Strother -- not accepted
  Dyssodia pentachaeta var. hartwegii (A. Gray) Strother -- not accepted
  Dyssodia polychaeta (A. Gray) B.L. Rob. -- not accepted
  Dyssodia porophylloides A. Gray -- not accepted
  Dyssodia setifolia var. greggii (A. Gray) M.C. Johnst. -- not accepted
  Dyssodia setifolia var. radiata (A. Gray) Strother -- not accepted
  Dyssodia tagetoides Torr. & A. Gray -- not accepted
  Dyssodia tenuiloba ssp. wrightii (A. Gray) Strother -- not accepted
  Dyssodia tenuiloba var. treculii (A. Gray) Strother -- not accepted
  Dyssodia thurberi (A. Gray) B.L. Rob. -- not accepted
  Dyssodia treculii (A. Gray) B.L. Rob. -- not accepted
  Dyssodia wrightii (A. Gray) B.L. Rob. -- not accepted
  Eatonella A. Gray -- accepted -- eatonella
  Eatonella congdonii A. Gray -- not accepted
  Eatonella nivea (D.C. Eaton) A. Gray -- accepted -- white eatonella, white false tickhead
  Eatonia obtusata (Michx.) A. Gray -- not accepted
  Eatonia pensylvanica (Spreng.) A. Gray -- not accepted
  Eatonia pensylvanica var. major (Torr.) A. Gray -- not accepted
  Eburophyton austiniae (A. Gray) A. Heller -- not accepted
  Echeveria strictiflora A. Gray -- accepted -- desert savior
  Echidiocarya californica A. Gray -- not accepted
  Echidiocarya californica var. ursina (A. Gray) Jeps. -- not accepted
  Echinocactus viridescens Torr. & A. Gray -- not accepted
  Echinocereus triglochidiatus var. melanacanthus (Engelm. ex A. Gray) L.D. Benson -- not accepted
  Echinocystis Torr. & A. Gray -- accepted
  Echinocystis lobata (Michx.) Torr. & A. Gray -- accepted -- wild balsamapple, wild cucumber, wild mock-cucumber, wild mockcucumber
  Echinodorus Rich. & Engelm. ex A. Gray -- accepted -- burhead
  Echinopepon coulteri (A. Gray) Rose -- accepted -- Coulter's balsam apple
  Echinopepon wrightii (A. Gray) S. Watson -- accepted -- wild balsam apple, wild balsam-apple
  Eddya hispidissima Torr. & A. Gray -- not accepted
  Elaphrium microphylla (A. Gray) Rose -- not accepted
  Elaterium wrightii A. Gray -- not accepted
  Elatine brachysperma A. Gray -- accepted -- short-seed waterwort, shortseed waterwort
  Elatine californica A. Gray -- accepted -- California waterwort
  Elatine texana (Hook.) Torr. & A. Gray -- not accepted
  Elatine triandra var. brachysperma (A. Gray) Fassett -- not accepted
  Eleocharis bolanderi A. Gray -- accepted -- Bolander's spikerush
  Eleocharis montevidensis var. bolanderi (A. Gray) V.E. Grant -- not accepted
  Eleocharis obtusa var. detonsa (A. Gray) Drapalik & Mohlenbr. -- not accepted
  Eleocharis ovata var. detonsa (A. Gray) Mohlenbr. -- not accepted
  Eleocharis wolfii (A. Gray) A. Gray ex Britton -- accepted -- wolf's spike-rush, Wolf's spikerush
  Elephantella attollens (A. Gray) A. Heller -- not accepted
  Elephantopus nudatus A. Gray -- accepted -- naked elephantfoot, smooth elephantsfoot
  Elymus striatus var. villosus (Muhl. ex Willd.) A. Gray -- not accepted
  Encelia farinosa A. Gray ex Torr. -- accepted -- brittlebush, goldenhills, white brittlebush
  Encelia farinosa var. farinosa A. Gray ex Torr. -- not accepted -- goldenhills
  Encelia frutescens (A. Gray) A. Gray -- accepted -- bush encelia, button brittlebush
  Encelia frutescens var. frutescens (A. Gray) A. Gray -- not accepted -- bush encelia, button brittlebush
  Encelia microcephala A. Gray -- not accepted
  Encelia nudicaulis A. Gray -- not accepted
  Encelia scaposa (A. Gray) A. Gray -- accepted -- onehead brittlebush, Scouler's silene
  Enceliopsis (A. Gray) A. Nelson -- accepted -- sunray
  Enceliopsis nudicaulis (A. Gray) A. Nelson -- accepted -- nakedstem sunray
  Enceliopsis nudicaulis var. nudicaulis (A. Gray) A. Nelson -- not accepted -- nakedstem sunray
  Enemion hallii (A. Gray) J.R. Drumm. & Hutch. -- accepted -- Willamette false rue anemone
  Enemion stipitatum (A. Gray) J.R. Drumm. & Hutch. -- accepted -- Siskiyou false rue anemone
  Engelmannia A. Gray ex Nutt. -- accepted -- Engelmann's daisy, engelmannia
  Engelmannia pinnatifida A. Gray ex Nutt. -- not accepted -- Engelmann's daisy
  Epilobium foliosum (Torr. & A. Gray) Suksd. -- accepted -- California willowherb, leafy willowherb
  Epilobium minutum var. foliosum Torr. & A. Gray -- not accepted
  Epilobium obcordatum A. Gray -- accepted -- rockfringe, rose willowweed
  Epilobium paniculatum Nutt. ex Torr. & A. Gray -- not accepted
  Epilobium paniculatum var. juncundum (A. Gray) Trel. -- not accepted
  Epilobium paniculatum var. paniculatum Nutt. ex Torr. & A. Gray -- not accepted
  Epixiphium (Engelm. ex A. Gray) Munz -- accepted
  Epixiphium wislizeni (Engelm. ex A. Gray) Munz -- accepted -- balloonbush
  Eragrostis brevipedicellata A. Gray -- not accepted
  Eragrostis pectinacea var. spectabilis (Pursh) A. Gray -- not accepted
  Eragrostis poaeoides var. megastachya (Koeler) A. Gray -- not accepted
  Eragrostis purshii Schrad. ex A. Gray -- not accepted
  Eragrostis tenuis A. Gray -- not accepted
  Eremalche exilis (A. Gray) Greene -- accepted -- white mallow, white-mallow
  Eremalche rotundifolia (A. Gray) Greene -- accepted -- desert five-spot, desert fivespot
  Eremocarya micrantha var. lepida (A. Gray) J.F. Macbr. -- not accepted
  Eremogone congesta var. suffrutescens (A. Gray) R.L. Hartm. & Rabeler -- accepted -- suffrutescent sandwort
  Eremogone fendleri (A. Gray) Ikonn. -- accepted -- Fendler's sandwort
  Eremothera chamaenerioides (A. Gray) W.L. Wagner & Hoch -- accepted -- longcapsule suncup
  Eriastrum diffusum (A. Gray) H. Mason -- accepted -- diffuse eriastrum, diffuse woolstar, miniature woollystar, miniature woolstar
  Ericameria albida (M.E. Jones ex A. Gray) L.C. Anderson -- accepted -- whiteflower rabbitbrush
  Ericameria arborescens (A. Gray) Greene -- accepted -- goldenfleece
  Ericameria bloomeri (A. Gray) J.F. Macbr. -- accepted -- Bloomer's goldenbush, rabbitbush
  Ericameria brachylepis (A. Gray) H.M. Hall -- accepted -- chaparral goldenbush
  Ericameria cooperi (A. Gray) H.M. Hall -- accepted -- Cooper's goldenbush, goldenbush
  Ericameria cooperi var. cooperi (A. Gray) H.M. Hall -- not accepted
  Ericameria cuneata (A. Gray) McClatchie -- accepted -- cliff goldenbush, cliff heath-goldenrod, cliff heathgoldenrod
  Ericameria cuneata var. cuneata (A. Gray) McClatchie -- accepted -- cliff goldenbush
  Ericameria cuneata var. spathulata (A. Gray) H.M. Hall -- accepted -- cliff goldenbush, cliff heathgoldenrod
  Ericameria greenei (A. Gray) G.L. Nesom -- accepted -- Greene's goldenbush, slender goldenrod
  Ericameria laricifolia (A. Gray) Shinners -- accepted -- ericameria, turpentine bush, turpentinebush
  Ericameria nauseosa ssp. consimilis var. leiosperma (A. Gray) G.L. Nesom & Baird -- not accepted
  Ericameria nauseosa ssp. nauseosa var. bigelovii (A. Gray) G.L. Nesom & Baird -- not accepted -- Bigelow rubber rabbitbrush
  Ericameria nauseosa ssp. nauseosa var. glabrata (A. Gray) G.L. Nesom & Baird -- not accepted -- green rubber rabbitbrush, rubber rabbitbrush
  Ericameria nauseosa ssp. nauseosa var. hololeuca (A. Gray) G.L. Nesom & Baird -- not accepted
  Ericameria nauseosa ssp. nauseosa var. latisquamea (A. Gray) G.L. Nesom & Baird -- not accepted
  Ericameria nauseosa var. bigelovii (A. Gray) G.L. Nesom & Baird -- accepted -- rubber rabbitbrush
  Ericameria nauseosa var. glabrata (A. Gray) G.L. Nesom & Baird -- not accepted -- rubber rabbitbrush
  Ericameria nauseosa var. hololeuca (A. Gray) G.L. Nesom & Baird -- accepted -- rubber rabbitbrush
  Ericameria nauseosa var. latisquamea (A. Gray) G.L. Nesom & Baird -- accepted -- rubber rabbitbrush
  Ericameria nauseosa var. leiosperma (A. Gray) G.L. Nesom & Baird -- accepted -- rubber rabbitbrush
  Ericameria palmeri (A. Gray) H.M. Hall -- accepted -- Palmer's goldenbush
  Ericameria palmeri var. palmeri (A. Gray) H.M. Hall -- accepted -- Palmer's rabbitbrush
  Ericameria paniculata (A. Gray) Rydb. -- accepted -- desert rabbitbrush, Mojave rabbitbrush
  Ericameria parryi (A. Gray) G.L. Nesom & Baird -- accepted -- Parry's goldenbush, Parry's rabbitbrush
  Ericameria parryi var. howardii (Parry ex A. Gray) G.L. Nesom & Baird -- accepted -- Parry's rabbitbrush
  Ericameria parryi var. nevadensis (A. Gray) G.L. Nesom & Baird -- accepted -- Parry's rabbitbrush
  Ericameria parryi var. parryi (A. Gray) G.L. Nesom & Baird -- accepted -- green rabbitbrush, Parry's rabbitbrush
  Ericameria pinifolia (A. Gray) H.M. Hall -- accepted -- pinebush
  Ericameria pulchella (A. Gray) L.C. Anderson -- not accepted
  Ericameria vaseyi (A. Gray) L.C. Anderson -- not accepted
  Ericameria viscidiflora var. stenophylla (A. Gray) L.C. Anderson -- not accepted
  Ericameria watsonii (A. Gray) G.L. Nesom -- accepted -- Watson's goldenbush, Watson's heath-goldenrod
  Ericameria X bolanderi (A. Gray) G.L. Nesom & Baird -- accepted
  Erigeron acris ssp. debilis (A. Gray) Piper -- not accepted -- bitter fleabane
  Erigeron acris var. debilis A. Gray -- not accepted
  Erigeron andersonii A. Gray -- not accepted
  Erigeron angulosus ssp. debilis (A. Gray) Piper -- not accepted
  Erigeron aphanactis (A. Gray) Greene -- accepted -- beach daisy, rayless shaggy fleabane
  Erigeron aphanactis var. aphanactis (A. Gray) Greene -- accepted -- rayless shaggy daisy, rayless shaggy fleabane
  Erigeron arenarioides (D.C. Eaton ex A. Gray) A. Gray ex Rydb. -- accepted -- sand fleabane
  Erigeron argentatus A. Gray -- accepted -- silver fleabane, silvery daisy
  Erigeron arizonicus A. Gray -- accepted -- Arizona fleabane
  Erigeron asperugineus (D.C. Eaton) A. Gray -- accepted -- Idaho daisy, Idaho fleabane
  Erigeron bigelovii A. Gray -- accepted -- Bigelow's fleabane
  Erigeron biglovii A. Gray -- not accepted
  Erigeron bloomeri A. Gray -- accepted -- Bloomer's daisy, scabland fleabane
  Erigeron bloomeri var. bloomeri A. Gray -- accepted -- scabland daisy, scabland fleabane
  Erigeron bloomeri var. nudatus (A. Gray) Cronquist -- accepted -- scabland fleabane
  Erigeron brandegeei A. Gray -- not accepted
  Erigeron breweri A. Gray -- accepted -- Brewer's daisy, Brewer's fleabane
  Erigeron breweri var. breweri A. Gray -- accepted -- Brewer's daisy, Brewer's fleabane
  Erigeron canadensis var. glabratus A. Gray -- not accepted
  Erigeron canus A. Gray -- accepted -- hoary fleabane
  Erigeron chrysopsidis A. Gray -- accepted -- dwarf yellow fleabane
  Erigeron chrysopsidis ssp. chrysopsidis A. Gray -- not accepted -- dwarf yellow fleabane
  Erigeron chrysopsidis var. chrysopsidis A. Gray -- accepted -- dwarf yellow fleabane
  Erigeron compositus var. discoideus A. Gray -- not accepted
  Erigeron compositus var. pinnatisectus A. Gray -- not accepted
  Erigeron concinnus (Hook. & Arn.) Torr. & A. Gray -- accepted -- hairy daisy, Navajo fleabane
  Erigeron concinnus var. aphanactis A. Gray -- not accepted
  Erigeron concinnus var. concinnus (Hook. & Arn.) Torr. & A. Gray -- accepted -- Navajo daisy, Navajo fleabane
  Erigeron debilis (A. Gray) Rydb. -- not accepted
  Erigeron delphiniifolius ssp. neomexicanus (A. Gray) Cronquist -- not accepted
  Erigeron divergens Torr. & A. Gray -- accepted -- spreading daisy, spreading fleabane
  Erigeron divergens var. cinereus A. Gray -- not accepted
  Erigeron eatonii A. Gray -- accepted -- Eaton's daisy, Eaton's fleabane
  Erigeron eatonii var. eatonii A. Gray -- accepted -- Eaton's daisy, Eaton's fleabane
  Erigeron elatior (A. Gray) Greene -- accepted -- tall fleabane
  Erigeron eriophyllis A. Gray -- not accepted
  Erigeron eriophyllus A. Gray -- not accepted
  Erigeron flagellaris A. Gray -- accepted -- trailing daisy, trailing fleabane
  Erigeron foliosus var. stenophyllus (Nutt.) A. Gray -- not accepted
  Erigeron glabellus var. mollis A. Gray -- not accepted
  Erigeron grandiflorus ssp. muirii (A. Gray) Hultén -- not accepted
  Erigeron grandiflorus var. elatior A. Gray -- not accepted
  Erigeron howellii A. Gray -- accepted -- Howell's fleabane
  Erigeron inornatus (A. Gray) A. Gray -- accepted -- California rayless fleabane, rayless daisy
  Erigeron inornatus var. angustatus A. Gray -- not accepted
  Erigeron inornatus var. inornatus (A. Gray) A. Gray -- accepted -- California rayless daisy, California rayless fleabane
  Erigeron inornatus var. viscidulus A. Gray -- not accepted
  Erigeron leiomerus A. Gray -- accepted -- glaber daisy, rockslide yellow fleabane
  Erigeron lemmonii A. Gray -- accepted -- Lemmon fleabane, Lemmon's fleabane
  Erigeron miser A. Gray -- accepted -- starved fleabane
  Erigeron modestus A. Gray -- accepted -- plains fleabane
  Erigeron muirii A. Gray -- accepted -- Muir's fleabane
  Erigeron neomexicanus A. Gray -- accepted -- New Mexico fleabane, oakbelt daisy
  Erigeron oreganus A. Gray -- accepted -- gorge fleabane
  Erigeron parishii A. Gray -- accepted -- Parish's daisy, Parish's fleabane
  Erigeron peregrinus ssp. callianthemus var. angustifolius (A. Gray) Cronquist -- not accepted -- subalpine fleabane
  Erigeron peregrinus ssp. callianthemus var. scaposus (Torr. & A. Gray) Cronquist -- not accepted -- subalpine fleabane
  Erigeron peregrinus var. angustifolius (A. Gray) Cronquist -- not accepted
  Erigeron peregrinus var. scaposus (Torr. & A. Gray) Cronquist -- not accepted
  Erigeron petrophilus var. viscidulus (A. Gray) G.L. Nesom -- accepted -- rockloving erigeron
  Erigeron peucephyllus A. Gray -- not accepted
  Erigeron pinnatisectus (A. Gray) A. Nelson -- accepted -- featherleaf fleabane
  Erigeron poliospermus A. Gray -- accepted -- purple cushion fleabane
  Erigeron poliospermus var. poliospermus A. Gray -- accepted -- purple cushion fleabane
  Erigeron pringlei A. Gray -- accepted -- Pringle's fleabane
  Erigeron pygmaeus (A. Gray) Greene -- accepted -- dwarf daisy, pygmy fleabane
  Erigeron ramosus var. beyrichii (Fisch. & C.A. Mey.) A. Gray -- not accepted
  Erigeron reductus var. angustatus (A. Gray) G.L. Nesom -- accepted -- lesser California rayless fleabane
  Erigeron repens A. Gray -- not accepted
  Erigeron rusbyi A. Gray -- not accepted
  Erigeron speciosus var. mollis (A. Gray) S.L. Welsh -- not accepted
  Erigeron strigosus var. beyrichii (Fisch. & C.A. Mey.) Torr. & A. Gray ex A. Gray -- not accepted -- Beyrich's fleabane
  Erigeron strigosus var. discoideus Robbins ex A. Gray -- not accepted
  Erigeron supplex A. Gray -- accepted -- supple fleabane
  Erigeron tener (A. Gray) A. Gray -- accepted -- slender daisy, slender fleabane
  Erigeron tenuis Torr. & A. Gray -- accepted -- slender fleabane, slenderleaf fleabane
  Erigeron thunbergii A. Gray -- accepted
  Erigeron thunbergii ssp. glabratus A. Gray -- accepted
  Erigeron thunbergii var. glabratus A. Gray -- not accepted
  Erigeron utahensis A. Gray -- accepted -- Utah fleabane
  Erigeron utahensis var. tetrapleuris (A. Gray) Cronquist -- not accepted
  Erigeron utahensis var. utahensis A. Gray -- accepted -- Utah fleabane
  Erigeron vernus (L.) Torr. & A. Gray -- accepted -- early whitetop fleabane
  Erigeron watsonii (A. Gray) Cronquist -- accepted -- Watson's daisy, Watson's fleabane
  Eriocarpum coloradoense (A. Gray) Greene -- not accepted
  Eriogonella leptoceras (A. Gray) Goodman -- not accepted
  Eriogonum brachypodum Torr. & A. Gray -- accepted -- Parry's buckwheat, Parry's wild buckwheat
  Eriogonum brevicaule var. laxifolium (Torr. & A. Gray) Reveal -- accepted -- goldenball eriogonum, shortstem buckwheat
  Eriogonum cernuum ssp. tenue (Torr. & A. Gray) S. Stokes -- not accepted
  Eriogonum cernuum var. tenue Torr. & A. Gray -- not accepted
  Eriogonum chrysocephalum A. Gray -- not accepted
  Eriogonum corymbosum var. divaricatum Torr. & A. Gray -- not accepted
  Eriogonum dasyanthemum Torr. & A. Gray -- accepted -- chaparral buckwheat
  Eriogonum deflexum ssp. watsonii (Torr. & A. Gray) S. Stokes -- not accepted
  Eriogonum deflexum var. brachypodum (Torr. & A. Gray) Munz -- not accepted
  Eriogonum deflexum var. watsonii (Torr. & A. Gray) R.J. Davis -- not accepted
  Eriogonum ericifolium Torr. & A. Gray -- accepted -- Yavapai buckwheat, Yavapai County buckwheat
  Eriogonum ericifolium var. ericifolium Torr. & A. Gray -- not accepted -- Yavapai buckwheat, Yavapai County buckwheat
  Eriogonum fasciculatum var. polifolium (Benth.) Torr. & A. Gray -- accepted -- Eastern Mojave buckwheat, flattop buckwheat, Mojave buckwheat
  Eriogonum greggii Torr. & A. Gray -- accepted -- Gregg's buckwheat
  Eriogonum heracleoides var. angustifolium (Nutt.) Torr. & A. Gray -- not accepted -- parsnipflower buckwheat
  Eriogonum hirtiflorum A. Gray ex S. Watson -- accepted -- hairyflower buckwheat
  Eriogonum incanum Torr. & A. Gray -- accepted -- frosted buckwheat
  Eriogonum kelloggii A. Gray -- accepted -- Red Mountain buckwheat
  Eriogonum kingii Torr. & A. Gray -- accepted -- Ruby Mountain buckwheat
  Eriogonum leptocladon Torr. & A. Gray -- accepted -- fine branched buckwheat, sand buckwheat
  Eriogonum leptocladon var. leptocladon Torr. & A. Gray -- accepted -- sand buckwheat
  Eriogonum leptophyllum (Torr. & A. Gray) Wooton & Standl. -- accepted -- slender-leaf buckwheat, slenderleaf buckwheat
  Eriogonum lobbii Torr. & A. Gray -- accepted -- granite buckwheat, Lobb's buckwheat
  Eriogonum lobbii var. lobbii Torr. & A. Gray -- not accepted -- Lobb's buckwheat
  Eriogonum lonchophyllum Torr. & A. Gray -- accepted -- spearleaf buckwheat, spreading wild buckwheat
  Eriogonum lonchophyllum var. lonchophyllum Torr. & A. Gray -- not accepted -- spearleaf buckwheat
  Eriogonum longifolium var. plantagineum Engelm. & A. Gray -- not accepted
  Eriogonum marifolium Torr. & A. Gray -- accepted -- marumleaf buckwheat
  Eriogonum marifolium var. incanum (Torr. & A. Gray) M.E. Jones -- not accepted
  Eriogonum marifolium var. marifolium Torr. & A. Gray -- accepted -- marumleaf buckwheat
  Eriogonum microthecum var. confertiflorum (Benth.) Torr. & A. Gray -- not accepted
  Eriogonum microthecum var. effusum (Nutt.) Torr. & A. Gray -- not accepted
  Eriogonum microthecum var. foliosum (Torr. & A. Gray) Reveal -- not accepted
  Eriogonum niveum var. decumbens (Benth.) Torr. & A. Gray -- not accepted
  Eriogonum nutans Torr. & A. Gray -- accepted -- drooping buckwheat, Dugway buckwheat
  Eriogonum nutans var. nutans Torr. & A. Gray -- accepted -- Dugway buckwheat
  Eriogonum parryi A. Gray -- not accepted
  Eriogonum proliferum Torr. & A. Gray -- not accepted
  Eriogonum pusillum Torr. & A. Gray -- accepted -- puny buckwheat, yellow-turbans, yellowturbans
  Eriogonum pyrolifolium var. coryphaeum Torr. & A. Gray -- accepted -- Shasta buckwheat
  Eriogonum reniforme ssp. pusillum (Torr. & A. Gray) S. Stokes -- not accepted
  Eriogonum spathulatum A. Gray -- accepted -- spoonleaf buckwheat
  Eriogonum spergulinum A. Gray -- accepted -- spurry buckwheat
  Eriogonum spergulinum var. spergulinum A. Gray -- accepted -- spurry buckwheat
  Eriogonum strictum ssp. proliferum (Torr. & A. Gray) S. Stokes -- not accepted -- Blue Mountain buckwheat
  Eriogonum strictum ssp. proliferum var. greenei (A. Gray) Reveal -- not accepted -- Greene's buckwheat
  Eriogonum strictum ssp. proliferum var. proliferum (Torr. & A. Gray) C.L. Hitchc. -- not accepted -- Blue Mountain buckwheat
  Eriogonum strictum var. greenei (A. Gray) Reveal -- accepted -- Greene's buckwheat
  Eriogonum strictum var. proliferum (Torr. & A. Gray) C.L. Hitchc. -- accepted -- Blue Mountain buckwheat
  Eriogonum tenellum var. caulescens Torr. & A. Gray -- not accepted
  Eriogonum torreyanum A. Gray -- not accepted
  Eriogonum truncatum Torr. & A. Gray -- accepted -- Contra Costa buckwheat, Mt. Diablo buckwheat
  Eriogonum umbellatum ssp. bahiiforme (Torr. & A. Gray) Munz -- not accepted
  Eriogonum umbellatum var. bahiiforme (Torr. & A. Gray) Jeps. -- accepted -- sulphur-flower buckwheat
  Eriogonum umbellatum var. monocephalum Torr. & A. Gray -- not accepted
  Eriogonum umbellatum var. torreyanum (A. Gray) M.E. Jones -- accepted -- Donner Pass buckwheat
  Eriogonum villiflorum A. Gray -- accepted -- dairyflower buckwheat, gray buckwheat
  Eriogonum watsonii Torr. & A. Gray -- accepted -- Watson's buckwheat
  Eriophorum crinigerum (A. Gray) Beetle -- accepted -- fringed cottongrass
  Eriophyllum ambiguum (A. Gray) A. Gray -- accepted -- beautiful woolly sunflower, beautiful woollysunflower
  Eriophyllum ambiguum var. ambiguum (A. Gray) A. Gray -- accepted -- beautiful woolly sunflower
  Eriophyllum confertiflorum (DC.) A. Gray -- accepted -- golden-yarrow, yellow-yarrow
  Eriophyllum confertiflorum var. confertiflorum (DC.) A. Gray -- accepted -- golden-yarrow
  Eriophyllum confertiflorum var. laxiflorum A. Gray -- not accepted
  Eriophyllum lanatum var. grandiflorum (A. Gray) Jeps. -- accepted -- common woolly sunflower
  Eriophyllum lanosum (A. Gray) A. Gray -- accepted -- white easterbonnets
  Eriophyllum multicaule (DC.) A. Gray -- accepted -- many-stem woolly-sunflower, manystem woolly sunflower
  Eriophyllum nevinii A. Gray -- not accepted -- Nevin's woolly sunflower
  Eriophyllum nubigenum Greene ex A. Gray -- accepted -- Yosemite woolly sunflower
  Eriophyllum pringlei A. Gray -- accepted -- Pringle's eriophyllum, Pringle's woolly sunflower, wooly sunflower
  Eriophyllum wallacei (A. Gray) A. Gray -- accepted -- woolly easterbonnets
  Eriophyllum wallacei var. rubellum (A. Gray) A. Gray -- not accepted
  Eritrichium holopterum A. Gray -- not accepted
  Eritrichium howardii (A. Gray) Rydb. -- accepted -- Howard's alpine forget-me-not
  Eritrichium oxygonum A. Gray -- not accepted
  Eritrichium pusillum Torr. & A. Gray -- not accepted
  Erodium texanum A. Gray -- accepted -- bull filaree, Texas filaree, Texas fillarie, Texas stork's bill, tufted filaree
  Eryngium aquaticum var. ravenelii (A. Gray) Mathias & Constance -- accepted -- rattlesnakemaster
  Eryngium leavenworthii Torr. & A. Gray -- accepted -- Leavenworth's eryngo
  Eryngium ravenelii A. Gray -- not accepted
  Eryngium synchaetum (A. Gray ex J.M. Coult. & Rose) J.M. Coult. & Rose -- not accepted
  Eryngium wrightii A. Gray -- not accepted
  Eryngium yuccifolium var. synchaetum A. Gray ex J.M. Coult. & Rose -- accepted -- button eryngo
  Erysimum asperum var. arkansanum (Nutt.) A. Gray -- not accepted
  Erysimum drummondii (A. Gray) Kuntze -- not accepted
  Erysimum petiolare (A. Gray) Kuntze -- not accepted
  Erysimum platyspermum (A. Gray) Kuntze -- not accepted
  Erythraea beyrichii Torr. & A. Gray -- not accepted
  Erythraea calycosa var. arizonica A. Gray -- not accepted
  Erythronium propullans A. Gray -- accepted -- Minnesota dwarf trout lily, Minnesota fawnlily, Minnesota trout lily
  Eschenbachia coulteri (A. Gray) Rydb. -- not accepted
  Eschenbachia tenuisecta (A. Gray) Woot. & Standl. -- not accepted
  Eschscholzia caespitosa var. hypecoides (Benth.) A. Gray -- not accepted
  Eschscholzia californica var. douglasii (Benth.) A. Gray -- not accepted
  Eucephalus breweri (A. Gray) G.L. Nesom -- accepted -- Brewer's aster
  Eucephalus glaucescens (A. Gray) Greene -- accepted -- Klickitat aster
  Eucephalus ledophyllus (A. Gray) Greene -- accepted -- Cascade aster
  Eucephalus ledophyllus var. ledophyllus (A. Gray) Greene -- accepted -- Cascade aster
  Eucnide aurea (A. Gray) H.J. Thomps. & W.R. Ernst -- accepted
  Eucnide urens (Parry ex A. Gray) Parry -- accepted -- desert rock nettle, desert stingbush, stingbush
  Eugenia sandwicensis A. Gray -- not accepted
  Eulobus Nutt. ex Torr. & A. Gray -- accepted
  Eulobus californicus Nutt. ex Torr. & A. Gray -- accepted -- California suncup
  Eunanus angustatus (A. Gray) Greene -- not accepted
  Eunanus bicolor A. Gray -- not accepted
  Eunanus bigelovii A. Gray -- not accepted
  Eunanus bolanderi (A. Gray) Greene -- not accepted
  Eunanus coulteri Harv. & A. Gray ex Benth. -- not accepted
  Eunanus coulteri var. angustatus A. Gray -- not accepted
  Eunanus leptaleus (A. Gray) Greene -- not accepted
  Eunanus rattanii (A. Gray) Greene -- not accepted
  Eunanus subsecundus (A. Gray) Greene -- not accepted
  Eunanus torreyi (A. Gray) Greene -- not accepted
  Eupatoriadelphus maculatus var. bruneri (A. Gray) King & H. Rob. -- not accepted
  Eupatorium album var. subvenosum A. Gray -- accepted -- white thoroughwort
  Eupatorium aromaticum var. incisum A. Gray -- not accepted
  Eupatorium bigelovii A. Gray -- not accepted -- Bigelow's thoroughwort
  Eupatorium bruneri A. Gray -- not accepted
  Eupatorium cuneatum (Engelm. ex A. Gray) Engelm. ex Small -- not accepted
  Eupatorium fendleri (A. Gray) A. Gray -- not accepted
  Eupatorium greggii A. Gray -- not accepted -- palmleaf thoroughwort
  Eupatorium herbaceum (A. Gray) Greene -- not accepted
  Eupatorium hyssopifolium var. laciniatum A. Gray -- accepted -- hyssopleaf thoroughwort
  Eupatorium lancifolium (Torr. & A. Gray) Small -- accepted -- lanceleaf thoroughwort
  Eupatorium leucolepis (DC.) Torr. & A. Gray -- accepted -- justiceweed
  Eupatorium leucolepis var. leucolepis (DC.) Torr. & A. Gray -- accepted -- justiceweed
  Eupatorium maculatum ssp. bruneri (A. Gray) G.W. Douglas -- not accepted
  Eupatorium maculatum var. bruneri (A. Gray) Breitung -- not accepted -- spotted joe-pye-weed, spotted joepyeweed
  Eupatorium parryi A. Gray -- not accepted
  Eupatorium pauperculum A. Gray -- not accepted
  Eupatorium perfoliatum var. cuneatum Engelm. ex A. Gray -- not accepted
  Eupatorium perfoliatum var. truncatum (Muhl. ex Willd.) A. Gray -- not accepted
  Eupatorium purpureum var. amoenum (Pursh) A. Gray -- not accepted
  Eupatorium rothrockii A. Gray -- not accepted
  Eupatorium rotundifolium var. scabridum (Elliot) A. Gray -- accepted -- roundleaf thoroughwort
  Eupatorium rugosum var. angustata (A. Gray) S.F. Blake -- not accepted
  Eupatorium semiserratum var. lancifolium Torr. & A. Gray -- not accepted
  Eupatorium solidaginifolium A. Gray -- not accepted -- shrubby thoroughwort
  Eupatorium sonorae A. Gray -- not accepted -- Sonoran thoroughwort
  Eupatorium texense (Torr. & A. Gray) Rydb. -- not accepted
  Eupatorium wrightii A. Gray -- not accepted
  Euphorbia albomarginata Torr. & A. Gray -- accepted -- Rattlesnake weed, white-margin sandmat, white-margin sandwort, whitemargin sandmat
  Euphorbia arenaria Engelm. & A. Gray -- not accepted
  Euphorbia arkansana Engelm. & A. Gray -- not accepted
  Euphorbia bicolor Engelm. & A. Gray -- accepted -- snow on the prairie, snow-on-the-prairie
  Euphorbia bicolor var. concolor Engelm. & A. Gray -- not accepted
  Euphorbia celastroides var. lorifolia (A. Gray ex H. Mann) Sherff -- not accepted -- `ekoko
  Euphorbia commutata Engelm. ex A. Gray -- accepted -- tinted euphorbia, tinted woodland spurge
  Euphorbia darlingtonii A. Gray -- not accepted
  Euphorbia dilatata Torr. & A. Gray -- not accepted
  Euphorbia fendleri Torr. & A. Gray -- accepted -- Fendler's sandmat
  Euphorbia geyeri var. microsperma A. Gray -- not accepted
  Euphorbia guilielmii A. Gray -- not accepted
  Euphorbia humistrata Engelm. ex A. Gray -- accepted -- spreading sandmat
  Euphorbia lorifolia (A. Gray ex H. Mann) Hillebr. -- not accepted
  Euphorbia marginata var. uloleuca Engelm. & A. Gray -- not accepted
  Euphorbia melanadenia Torr. & A. Gray -- accepted -- prostrate spurge, red-gland spurge, squaw sandmat
  Euphorbia multiformis var. celastroides A. Gray -- not accepted
  Euphorbia multiformis var. lorifolia A. Gray ex H. Mann -- not accepted
  Euphorbia multiformis var. tenuior A. Gray ex H. Mann -- not accepted
  Euphorbia remyi A. Gray ex Boiss. -- accepted -- Remy's sandmat
  Euphorbia remyi var. remyi A. Gray ex Boiss. -- accepted -- Remy's sandmat
  Euphorbia wrightii Torr. & A. Gray -- accepted -- Wright's spurge
  Eurya sandwicensis A. Gray -- accepted -- anini
  Eurybia chapmanii (Torr. & A. Gray) G.L. Nesom -- not accepted -- savannah aster
  Eurybia eryngiifolia (Torr. & A. Gray) G.L. Nesom -- accepted -- thistleleaf aster
  Eurybia mirabilis (Torr. & A. Gray) G.L. Nesom -- accepted -- bouquet aster
  Eurybia radulina (A. Gray) G.L. Nesom -- accepted -- roughleaf aster
  Eurybia X herveyi (A. Gray) G.L. Nesom -- accepted
  Eurytaenia Torr. & A. Gray -- accepted -- spreadwing
  Eurytaenia texana Torr. & A. Gray -- accepted -- Texas spreadwing
  Eustylis Engelm. & A. Gray -- not accepted
  Eustylis purpurea (Herb.) Engelm. & A. Gray -- not accepted
  Euthamia leptocephala (Torr. & A. Gray) Greene ex Porter & Britton -- accepted -- bushy goldentop
  Eutrochium maculatum var. bruneri (A. Gray) E.E. Lamont -- accepted -- spotted joepyeweed
  Evax candida (Torr. & A. Gray) A. Gray -- not accepted -- silver evax, silver pygmycudweed
  Evax caulescens var. petiolata A. Gray -- not accepted
  Evax multicaulis var. drummondii (Torr. & A. Gray) A. Gray -- not accepted
  Evax sparsiflora (A. Gray) Jeps. -- not accepted
  Evax sparsiflora var. brevifolia (A. Gray) Jeps. -- not accepted
  Evax verna var. drummondii (Torr. & A. Gray) Kartesz & Gandhi -- not accepted -- spring pygmycudweed
  Evolvulus arizonicus A. Gray -- accepted -- hairy evolvulus, wild dwarf morning-glory, wild dwarf morningglory
  Evolvulus arizonicus var. laetus (A. Gray) Ooststr. -- not accepted
  Evolvulus laetus A. Gray -- not accepted
  Evolvulus sericeus var. discolor (Benth.) A. Gray -- not accepted
  Eysenhardtia orthocarpa (A. Gray) S. Watson -- accepted -- Tahitian kidneywood
  Fagraea berteriana A. Gray ex Benth. -- not accepted
  Fagraea berteroana A. Gray ex Benth. -- accepted
  Falcata pitcheri (Torr. & A. Gray) Kuntze -- not accepted
  Fendlera Engelm. & A. Gray -- accepted -- fendlerbush
  Fendlera rupicola Engelm. & A. Gray -- accepted -- cliff fendlerbush, fendlerbush
  Fendlera rupicola var. rupicola A. Gray -- accepted -- cliff fendlerbush
  Fendlera rupicola var. wrightii A. Gray -- accepted -- Wright's fendlerbush
  Fendlera wrightii (A. Gray) A. Heller -- not accepted -- Wright's fendlerbush
  Ferocactus viridescens (Torr. & A. Gray) Britton & Rose -- accepted -- Biznaga-barril verdosa, coast barrel cactus, San Diego barrel cactus
  Festuca acerosa Trin. ex A. Gray -- not accepted
  Festuca elatior var. pratensis (Huds.) A. Gray -- not accepted
  Festuca macrostachya Torr. & A. Gray -- not accepted
  Festuca microstachys var. ciliata A. Gray -- not accepted
  Festuca microstachys var. ciliata A. Gray ex Beal -- not accepted
  Festuca pacifica var. ciliata (A. Gray) Hoover -- not accepted
  Filaginopsis drummondii Torr. & A. Gray -- not accepted
  Filaginopsis multicaulis (DC.) Torr. & A. Gray -- not accepted
  Filago arizonica A. Gray -- not accepted -- Arizona cottonrose
  Filago candida (Torr. & A. Gray) Shinners -- not accepted
  Filago depressa A. Gray -- not accepted -- dwarf cottonrose, dwarf filago
  Filago verna var. drummondii (Torr. & A. Gray) Shinners -- not accepted
  Fimbristylis capillaris (L.) A. Gray -- not accepted
  Flaveria chlorifolia A. Gray -- accepted -- clasping yellowtops
  Fleischmannia sonorae (A. Gray) King & H. Rob. -- accepted -- Sonoran thoroughwort
  Flourensia pringlei (A. Gray) S.F. Blake -- accepted -- Pringle's tarwort
  Flyriella parryi (A. Gray) King & H. Rob. -- accepted -- Chisos Mountain brickellbush
  Forestiera acuminata var. parviflora A. Gray -- not accepted
  Forestiera neomexicana A. Gray -- not accepted
  Forestiera neomexicana var. arizonica A. Gray -- not accepted
  Forestiera pubescens ssp. neomexicana (A. Gray) E.A. Murray -- not accepted
  Forestiera pubescens var. neomexicana (A. Gray) E.A. Murray -- not accepted
  Forsellesia nevadensis (A. Gray) Greene -- not accepted
  Forsellesia spinescens (A. Gray) Greene -- not accepted
  Fragaria virginiana var. illinoensis A. Gray -- not accepted
  Frangula californica (Eschsch.) A. Gray -- not accepted -- California buckthorn
  Frangula californica ssp. californica (Eschsch.) A. Gray -- not accepted -- California buckthorn
  Frangula caroliniana (Walter) A. Gray -- not accepted -- Carolina buckthorn
  Frangula purshiana (DC.) A. Gray -- not accepted -- Cascara buckthorn, Pursh's buckthorn
  Frankenia grandifolia var. campestris A. Gray -- not accepted
  Frankenia jamesii Torr. ex A. Gray -- accepted -- frank bush, James' seaheath
  Franseria cordifolia A. Gray -- not accepted
  Franseria dumosa A. Gray -- not accepted
  Franseria eriocentra A. Gray -- not accepted
  Franseria ilicifolia A. Gray -- not accepted
  Franseria tomentosa (Nutt.) A. Nelson, non A. Gray -- not accepted -- bur ragweed
  Franseria tomentosa A. Gray -- not accepted
  Frasera albicaulis var. cusickii (A. Gray) C.L. Hitchc. -- accepted -- Cusick's frasera
  Fraxinus americana ssp. texensis (A. Gray) G.N. Mill. -- not accepted
  Fraxinus americana var. microcarpa A. Gray -- not accepted
  Fraxinus americana var. texensis A. Gray -- not accepted
  Fraxinus greggii A. Gray -- accepted -- Gregg's ash
  Fraxinus texensis (A. Gray) Sarg. -- accepted -- Texas ash
  Funastrum hirtellum (A. Gray) Schltr. -- accepted -- hairy milkweed
  Funastrum torreyi (A. Gray) Schltr. -- accepted -- soft twinevine
  Gaertnera tomentosa (A. Gray) Kuntze -- not accepted
  Gaertneria tenuifolia Harv. & A. Gray -- not accepted
  Gaillardia arizonica A. Gray -- accepted -- Arizona blanketflower, Pringle's blanketflower
  Gaillardia arizonica var. arizonica A. Gray -- not accepted -- Arizona blanketflower
  Gaillardia mexicana auct. non A. Gray -- not accepted
  Gaillardia pulchella var. picta (D. Don) A. Gray -- not accepted -- firewheel
  Gaillardia spathulata A. Gray -- accepted -- western blanketflower
  Gaillardia spatulata A. Gray -- not accepted
  Gaillardia suavis (A. Gray & Engelm.) Britton & Rusby -- accepted -- perfumeballs, sweet gaillardia
  Galactia brachypoda Torr. & A. Gray -- not accepted
  Galactia elliottii var. leavenworthii Torr. & A. Gray -- not accepted
  Galactia floridana Torr. & A. Gray -- accepted -- Florida milkpea
  Galactia heterophylla A. Gray -- accepted -- Gray's milkpea
  Galactia spiciformis Torr. & A. Gray -- not accepted
  Galactia texana (Scheele) A. Gray -- accepted -- Texas milkpea
  Galactia wrightii A. Gray -- accepted -- Wright milkpea, Wright's milkpea
  Galactia wrightii var. wrightii A. Gray -- accepted -- Wright milkpea, Wright's milkpea
  Galarhoeus arkansanus (Engelm. & A. Gray) Small ex Rydb. -- not accepted
  Galarhoeus commutatus (Engelm. ex A. Gray) Small ex Rydb. -- not accepted
  Galarhoeus darlingtonii (A. Gray) Small -- not accepted
  Galinsoga parviflora var. semicalva A. Gray -- accepted
  Galinsoga semicalva (A. Gray) H. St. John & D. White -- not accepted
  Galium andrewsii A. Gray -- accepted -- phloxleaf bedstraw
  Galium andrewsii ssp. andrewsii A. Gray -- accepted -- Andrews' bedstraw
  Galium angustifolium Nutt. ex Torr. & A. Gray -- accepted -- narrowleaf bedstraw
  Galium angustifolium ssp. angustifolium Nutt. ex A. Gray -- accepted -- narrowleaf bedstraw
  Galium arkansanum A. Gray -- accepted -- Arkansas bedstraw
  Galium asperrimum A. Gray -- not accepted
  Galium asperrimum var. asperulum A. Gray -- not accepted
  Galium asperulum (A. Gray) Rydb. -- not accepted
  Galium bloomeri A. Gray -- not accepted
  Galium bloomeri var. hirsutum A. Gray -- not accepted
  Galium bolanderi A. Gray -- accepted -- Bolander's bedstraw
  Galium brandegeei A. Gray -- not accepted
  Galium californicum var. texanum Torr. & A. Gray -- not accepted
  Galium catalinense A. Gray -- accepted -- Santa Catalina Island bedstraw
  Galium catalinense ssp. catalinense A. Gray -- accepted -- Santa Catalina Island bedstraw
  Galium circaezans var. lanceolatum (Torr.) Torr. & A. Gray -- not accepted
  Galium concinnum Torr. & A. Gray -- accepted -- shining bedstraw
  Galium fendleri A. Gray -- accepted -- Fendler's bedstraw
  Galium hypotrichium A. Gray -- accepted -- alpine bedstraw
  Galium hypotrichium ssp. hypotrichium A. Gray -- accepted -- alpine bedstraw
  Galium margaricoccum A. Gray -- not accepted
  Galium matthewsii A. Gray -- accepted -- bushy bedstraw, Matthew bedstraw
  Galium mexicanum ssp. asperrimum (A. Gray) Dempster -- accepted -- Mexican bedstraw
  Galium mexicanum ssp. asperulum (A. Gray) Dempster -- accepted -- Mexican bedstraw
  Galium mexicanum var. asperrimum (A. Gray) Higgins & S.L. Welsh -- not accepted
  Galium mexicanum var. asperulum (A. Gray) Dempster -- not accepted
  Galium microphyllum A. Gray -- accepted -- bracted bedstraw
  Galium multiflorum var. hirsutum (A. Gray) Jeps. -- not accepted
  Galium multiflorum var. watsonii A. Gray -- not accepted
  Galium nuttallii A. Gray -- accepted -- climbing bedstraw
  Galium nuttallii ssp. nuttallii A. Gray -- accepted -- climbing bedstraw
  Galium pilosum var. puncticulosum (Michx.) Torr. & A. Gray -- accepted -- hairy bedstraw
  Galium proliferum A. Gray -- accepted -- limestone bedstraw
  Galium pubens A. Gray -- not accepted
  Galium pubens var. scabridum A. Gray -- not accepted
  Galium rothrockii A. Gray -- not accepted
  Galium texanum (Torr. & A. Gray) Wiegand -- not accepted
  Galium texense A. Gray -- accepted -- Texas bedstraw
  Galium trifidum var. pusillum A. Gray -- not accepted
  Galium trifidum var. tinctorium (L.) Torr. & A. Gray -- not accepted
  Galium virgatum var. diffusum A. Gray -- not accepted
  Galium virgatum var. leiocarpum Torr. & A. Gray -- not accepted
  Galium watsonii (A. Gray) A. Heller -- accepted -- Watson's bedstraw
  Galium wrightii A. Gray -- accepted -- slenderbranch bedstraw, Wright's bedstraw
  Galium wrightii var. rothrockii (A. Gray) Ehrend. ex Ferris -- not accepted
  Galpinsia lavandulifolia (Torr. & A. Gray) Small -- not accepted
  Galvezia speciosa (Nutt.) A. Gray -- not accepted -- island snapdragon
  Garberia A. Gray -- accepted -- garberia
  Garberia fruticosa (Nutt.) A. Gray -- not accepted
  Garrya buxifolia A. Gray -- accepted -- dwarf silktassel
  Gatesia laetevirens (Buckley) A. Gray -- not accepted
  Gaultheria ovatifolia A. Gray -- accepted -- western teaberry
  Gaura biennis var. pitcheri Torr. & A. Gray -- not accepted
  Gaura drummondii (Spach) Torr. & A. Gray -- not accepted -- Drummond's beeblossom, scented gaura
  Gaura filipes var. major Torr. & A. Gray -- not accepted
  Gaura lindheimeri Engelm. & A. Gray -- not accepted -- Lindheimer's beeblossom, white gaura
  Gaura pitcheri (Torr. & A. Gray) Small -- not accepted
  Gaylussacia brachycera (Michx.) A. Gray -- accepted -- box huckleberry
  Gaylussacia dumosa (Andrews) Torr. & A. Gray -- accepted -- dwarf huckleberry
  Gaylussacia dumosa var. dumosa (Andrews) Torr. & A. Gray -- not accepted -- dwarf huckleberry
  Gaylussacia frondosa (L.) Torr. & A. Gray -- accepted -- blue huckleberry, dangleberry
  Gaylussacia frondosa var. frondosa (L.) Torr. & A. Gray -- not accepted
  Gaylussacia frondosa var. nana A. Gray -- not accepted -- blue huckleberry
  Gaylussacia frondosa var. tomentosa A. Gray -- not accepted
  Gaylussacia nana (A. Gray) Small -- accepted -- Confederate huckleberry, dwarf dangleberry
  Gaylussacia tomentosa (A. Gray) Pursh ex Small -- accepted -- hairytwig dangleberry, hairytwig huckleberry
  Gaylussacia ursina (M.A. Curtis) Torr. & A. Gray -- accepted -- bear huckleberry
  Gayophytum diffusum Torr. & A. Gray -- accepted -- bigflower groundsmoke, spreading groundsmoke
  Gayophytum diffusum ssp. diffusum Torr. & A. Gray -- accepted -- spreading groundsmoke
  Gayophytum nuttallii Torr. & A. Gray -- not accepted
  Gayophytum racemosum Torr. & A. Gray -- accepted -- black-foot groundsmoke, blackfoot groundsmoke
  Gayophytum racemosum var. caesium (Torr. & A. Gray) Munz -- not accepted
  Gayophytum ramosissimum Torr. & A. Gray -- accepted -- muchbranched groundsmoke, pinyon groundsmoke
  Gayophytum strictum A. Gray -- not accepted
  Gentiana affinis var. bigelovii (A. Gray) Kusnez. -- not accepted
  Gentiana affinis var. forwoodii (A. Gray) Kusnez. -- not accepted
  Gentiana affinis var. ovata A. Gray -- not accepted
  Gentiana bigelovii A. Gray -- not accepted
  Gentiana flavida A. Gray -- not accepted
  Gentiana forwoodii A. Gray -- not accepted
  Gentiana grandis (A. Gray) T. Holm -- not accepted
  Gentiana holopetala (A. Gray) T. Holm -- not accepted
  Gentiana linearis var. lanceolata A. Gray -- not accepted
  Gentiana linearis var. latifolia A. Gray -- not accepted
  Gentiana newberryi A. Gray -- accepted -- alpine gentian
  Gentiana newberryi var. newberryi A. Gray -- accepted -- alpine gentian
  Gentiana oregana Engelm. ex A. Gray -- not accepted
  Gentiana quinquefolia var. occidentalis A. Gray -- not accepted
  Gentiana sceptrum var. humilis Engelm. ex A. Gray -- not accepted
  Gentiana setigera auct. non A. Gray -- not accepted
  Gentiana setigera A. Gray -- accepted -- Mendocino gentian
  Gentiana simplex A. Gray -- not accepted
  Gentiana wrightii A. Gray -- not accepted
  Gentianella amarella ssp. wrightii (A. Gray) J.M. Gillett -- not accepted -- Wright's dwarfgentian
  Gentianella detonsa ssp. holopetala (A. Gray) J.M. Gillett -- not accepted
  Gentianella occidentalis (A. Gray) Small -- not accepted
  Gentianella quinquefolia ssp. occidentalis (A. Gray) J.M. Gillett -- accepted -- agueweed
  Gentianella simplex (A. Gray) J.M. Gillett -- not accepted
  Gentianella wrightii (A. Gray) Holub -- accepted -- Wright's dwarf gentian
  Gentianopsis holopetala (A. Gray) Iltis -- accepted -- Sierra fringed gentian, Sierra gentian
  Gentianopsis simplex (A. Gray) Iltis -- accepted -- oneflower fringed gentian, oneflower gentian
  Geoprumnon tennesseense (A. Gray ex Chapm.) Rydb. -- not accepted
  Geraea Torr. & A. Gray -- accepted -- desert sunflower, desertsunflower
  Geraea canescens Torr. & A. Gray -- accepted -- desert sunflower, desertgold, hairy desertsunflower
  Geraea canescens var. canescens Torr. & A. Gray -- not accepted -- hairy desert sunflower, hairy desertsunflower
  Geraea canescens var. paniculata (A. Gray) S.F. Blake -- not accepted -- hairy desert sunflower, hairy desertsunflower
  Geraea viscida (A. Gray) S.F. Blake -- accepted -- sticky desertsunflower
  Geranium arboreum A. Gray -- accepted -- Hawai'i red cranesbill, Hawaiian red-flowered geranium
  Geranium caespitosum var. fremontii (Torr. ex A. Gray) Dorn -- not accepted -- Fremont's geranium
  Geranium cuneatum ssp. hololeucum (A. Gray) Carlquist & Bissing -- accepted -- hinahina
  Geranium cuneatum ssp. hypoleucum (A. Gray) Carlquist & Bissing -- accepted -- hinahina
  Geranium cuneatum var. hololeucum A. Gray -- not accepted -- hinahina
  Geranium cuneatum var. hypoleucum A. Gray -- not accepted -- hinahina
  Geranium cuneatum var. menziesii A. Gray -- not accepted
  Geranium fremontii Torr. ex A. Gray -- not accepted
  Geranium multiflorum A. Gray -- accepted -- manyflower geranium, nohoanu
  Geranium multiflorum ssp. ovatifolium (A. Gray) Carlquist & Bissing -- not accepted
  Geranium multiflorum var. ovatifolium (A. Gray) Fosberg -- not accepted
  Geranium ovatifolium A. Gray -- not accepted
  Geranium viscosissimum var. incisum (Torr. & A. Gray) N.H. Holmgren -- accepted -- sticky purple geranium
  Gerardia barbata (Torr. & A. Gray) S.F. Blake -- not accepted
  Gerardia dulcis var. floridana (A. Gray) S.F. Blake -- not accepted
  Gerardia floridana (A. Gray) Small -- not accepted
  Gerardia microphylla (A. Gray) Small -- not accepted
  Gerardia patula (Chapm.) A. Gray -- not accepted
  Gerardia paupercula (A. Gray) Britton -- not accepted
  Gerardia plukenetii var. microphylla A. Gray -- not accepted
  Gerardia purpurea var. paupercula A. Gray -- not accepted
  Geum vernum (Raf.) Torr. & A. Gray -- accepted -- heartleaf avens, spring avens
  Gilia acerosa (A. Gray) Britton -- not accepted
  Gilia aggregata var. attenuata A. Gray -- not accepted
  Gilia aggregata var. bridgesii A. Gray -- not accepted
  Gilia attenuata (A. Gray) A. Nelson -- not accepted
  Gilia bigelovii A. Gray -- not accepted
  Gilia brandegeei A. Gray -- not accepted
  Gilia bridgesii (A. Gray) Wherry -- not accepted
  Gilia caespitosa A. Gray -- not accepted -- Rabbit Valley gilia
  Gilia campanulata A. Gray -- not accepted -- bellflower gilia, bellshape gilia
  Gilia congesta var. crebrifolia (Nutt.) A. Gray -- not accepted
  Gilia depressa M.E. Jones ex A. Gray -- not accepted
  Gilia filiformis Parry ex A. Gray -- not accepted -- yellow gilia, yellow gily-flower
  Gilia gunnisonii Torr. & A. Gray -- not accepted
  Gilia havardii A. Gray -- not accepted
  Gilia haydenii A. Gray -- not accepted -- San Juan gilia
  Gilia inconspicua var. sinuata (Douglas ex Benth.) A. Gray -- not accepted
  Gilia latiflora (A. Gray) A. Gray -- accepted -- hollyleaf gilia
  Gilia latiflora ssp. exilis (A. Gray) H. Mason & A.D. Grant -- not accepted
  Gilia latiflora ssp. latiflora (A. Gray) A. Gray -- accepted -- hollyleaf gilia
  Gilia leptalea (A. Gray) Greene -- not accepted -- Bridges' gilia
  Gilia leptalea ssp. leptalea (A. Gray) Greene -- not accepted -- Bridges' gilia
  Gilia leptomeria A. Gray -- not accepted -- sand gilia, sand gily-flower, slender gilia
  Gilia leptomeria ssp. micromeria (A. Gray) H. Mason & A.D. Grant -- not accepted
  Gilia leptomeria var. micromeria (A. Gray) Cronquist -- not accepted
  Gilia macombii Torr. ex A. Gray -- not accepted
  Gilia micromeria A. Gray -- not accepted -- dainty gilia
  Gilia multicaulis ssp. nevinii (A. Gray) H. Mason & A.D. Grant -- not accepted
  Gilia nevinii A. Gray -- accepted -- Nevin's gilia
  Gilia nuttallii A. Gray -- not accepted
  Gilia ochroleuca ssp. exilis (A. Gray) A.D. Grant & V.E. Grant -- accepted -- volcanic gilia
  Gilia pinnatifida Nutt. ex A. Gray -- not accepted -- sticky gilia
  Gilia pringlei auct. non A. Gray -- not accepted
  Gilia pungens var. hookeri (Douglas ex Hook.) A. Gray -- not accepted
  Gilia rigidula ssp. acerosa (A. Gray) Wherry -- not accepted -- bluebowls
  Gilia rigidula var. acerosa A. Gray -- not accepted
  Gilia spicata var. capitata A. Gray -- not accepted
  Gilia stenothyrsa A. Gray -- not accepted -- Uinta Basin gilia
  Gilia subnuda Torr. ex A. Gray -- not accepted -- Canyon Lands gilia, coral gilia, coral gily-flower
  Gilia subnuda ssp. haydenii (A. Gray) Brand -- not accepted
  Gilia tenerrima A. Gray -- not accepted -- delicate gilia
  Gilia thurberi (Torr. ex A. Gray) A. Gray -- not accepted
  Gilia wrightii A. Gray -- not accepted
  Giliastrum acerosum (A. Gray) Rydb. -- accepted -- bluebowls
  Giliastrum rigidulum ssp. acerosum (A. Gray) W.A. Weber -- not accepted
  Githopsis diffusa A. Gray -- accepted -- San Gabriel bluecup
  Githopsis diffusa ssp. diffusa A. Gray -- accepted -- San Gabriel bluecup
  Glandularia wrightii (A. Gray) Umber -- not accepted -- Davis Mountain mock vervain, Wright's verbena
  Glossopetalon A. Gray -- accepted -- greasebush
  Glossopetalon nevadense A. Gray -- not accepted
  Glossopetalon spinescens A. Gray -- accepted -- spiny greasebush
  Glossopetalon spinescens var. spinescens A. Gray -- accepted -- spiny greasebush, thorny greasebush
  Glyceria spectabilis var. flaccida Trin. & Bong. ex A. Gray -- not accepted
  Glycosma occidentalis Nutt. ex Torr. & A. Gray -- not accepted
  Glyptopleura setulosa A. Gray -- accepted -- holy dandelion, holy-dandelion, largeflower carveseed
  Gnaphalium arizonicum A. Gray -- not accepted
  Gnaphalium leucocephaluim A. Gray -- not accepted
  Gnaphalium leucocephalum A. Gray -- not accepted
  Gnaphalium pringlei A. Gray -- not accepted
  Gnaphalium purpureum var. falcatum (Lam.) Torr. & A. Gray -- not accepted
  Gnaphalium wrightii A. Gray -- not accepted
  Gochnatia hypoleuca (DC.) A. Gray -- accepted -- shrubby bullseye
  Godetia epilobioides (Nutt. ex Torr. & A. Gray) S. Watson -- not accepted
  Godetia whitneyi (A. Gray) T. Moore -- not accepted
  Gomphocarpus cordifolius (Benth.) Benth. ex A. Gray -- not accepted
  Gonolobus arizonicus (A. Gray) Woodson -- accepted -- Arizona milkvine
  Gonolobus cynanchoides Engelm. & A. Gray -- not accepted
  Gonolobus reticulatus Engelm. ex A. Gray -- not accepted
  Gonolobus sagittifolius A. Gray -- not accepted
  Gonolobus shortii (A. Gray) A. Gray -- not accepted
  Gormania obtusata (A. Gray) Britton -- not accepted
  Gouania vitifolia A. Gray -- accepted -- Oahu chewstick
  Gouldia A. Gray -- not accepted
  Gouldia A. Gray -- not accepted
  Gouldia hirtella (A. Gray) Hillebr. -- not accepted
  Graphephorum cooleyi (A. Gray) Farw. -- not accepted
  Graphephorum festucaceum (Willd.) A. Gray -- not accepted
  Graphephorum fisheri (R. Br.) A. Gray -- not accepted
  Graphephorum fisheri var. fisheri (R. Br.) A. Gray -- not accepted
  Graphephorum fisheri var. psilosanthum (Rupr.) A. Gray -- not accepted
  Graphephorum flexuosum Thurb. ex A. Gray -- not accepted
  Graphephorum fulvum (Trin.) A. Gray -- not accepted
  Graphephorum melicoides var. cooleyi (A. Gray) Scribn. -- not accepted
  Graphephorum melicoides var. majus A. Gray -- not accepted
  Graphephorum pendulina (Laest.) A. Gray -- not accepted
  Grayia brandegeei A. Gray -- accepted -- Brandegee's siltbush, siltbush, spineless hopsage
  Greenella A. Gray -- accepted
  Greenella arizonica A. Gray -- not accepted
  Greenella discoidea A. Gray -- not accepted
  Greggia camporum A. Gray -- not accepted
  Gregoria montana (A. Gray) House -- not accepted
  Grindelia arizonica A. Gray -- accepted -- Arizona gumweed, cutleaf gumweed, New Mexican gumweed
  Grindelia arizonica var. arizonica A. Gray -- not accepted -- Arizona gumweed
  Grindelia gymnospermoides (A. Gray) Ruffin -- not accepted
  Grindelia nana var. discoidea (Nutt.) A. Gray -- not accepted
  Grindelia robusta var. angustifolia A. Gray -- not accepted
  Grindelia squarrosa var. nuda (Alph. Wood) A. Gray -- not accepted
  Grindelia stricta var. angustifolia (A. Gray) M.A. Lane -- not accepted -- Oregon gumweed
  Grossularia lobbii (A. Gray) Coville & Britton -- not accepted
  Guaiacum coulteri A. Gray -- accepted
  Guardiola platyphylla A. Gray -- accepted -- Apache plant
  Gundlachia A. Gray -- accepted -- gundlachia
  Gundlachia A. Gray -- not accepted
  Gutierrezia arizonica (A. Gray) M.A. Lane -- accepted -- Arizona snakeweed
  Gutierrezia californica (DC.) Torr. & A. Gray -- accepted -- California snakeweed, San Joaquin snakeweed
  Gutierrezia eriocarpa A. Gray -- not accepted
  Gutierrezia gymnospermoides A. Gray -- not accepted
  Gutierrezia microcephala (DC.) A. Gray -- accepted -- threadleaf snakeweed
  Gutierrezia sphaerocephala A. Gray -- accepted -- round-leaf snakeweed, roundleaf snakeweed
  Gutierrezia texana (DC.) Torr. & A. Gray -- accepted -- Texas broomweed, Texas snakeweed
  Gutierrezia texana var. texana (DC.) Torr. & A. Gray -- accepted -- Texas snakeweed
  Gutierrezia wrightii A. Gray -- accepted -- Wright's snakeweed
  Gymnolomia hispida (A. Gray) B.L. Rob. & Greenm. -- not accepted
  Habenaria hookeri Torr. ex A. Gray -- not accepted
  Habenaria leucophaea (Nutt.) A. Gray -- not accepted
  Habenaria peramoena A. Gray -- not accepted
  Habenaria psycodes var. grandiflora (Bigelow) A. Gray -- not accepted
  Habenaria viridis var. bracteata (Muhl.) A. Gray -- not accepted
  Hackelia americana (A. Gray) Fernald -- not accepted
  Hackelia californica (A. Gray) I.M. Johnst. -- accepted -- California stickseed
  Hackelia deflexa ssp. americana (A. Gray) Á. Löve & D. Löve -- not accepted
  Hackelia deflexa var. americana (A. Gray) Fernald & I.M. Johnst. -- accepted -- American stickseed, nodding stickseed
  Hackelia hispida (A. Gray) I.M. Johnst. -- accepted -- showy stickseed
  Hackelia hispida var. hispida (A. Gray) I.M. Johnst. -- accepted -- showy stickseed
  Hackelia pinetorum (Greene ex A. Gray) I.M. Johnst. -- accepted -- Livermore stickseed
  Hackelia pinetorum var. pinetorum (Greene ex A. Gray) I.M. Johnst. -- accepted -- Livermore stickseed
  Hackelia ursina (Greene ex A. Gray) I.M. Johnst. -- accepted -- Chihuahuan stickseed
  Hackelia ursina var. ursina (Greene ex A. Gray) I.M. Johnst. -- accepted -- Chihuahuan stickseed
  Halea ludoviciana Torr. & A. Gray -- not accepted
  Halenia deflexa var. brentoniana (Griseb.) A. Gray -- not accepted
  Halenia rothrockii A. Gray -- accepted -- Mt. Graham spurred gentian, southwest spurred gentian
  Halimolobos diffusa (A. Gray) O.E. Schulz -- accepted -- spreading fissurewort, spreading halimolobos
  Halimolobos diffusa var. diffusa (A. Gray) O.E. Schulz -- not accepted -- spreading fissurewort
  Halimolobos pubens (A. Gray) Al-Shehbaz & C.D. Bailey -- accepted -- Trans-Pecos cress
  Hamosa leptocarpa (Torr. & A. Gray) Rydb. -- not accepted
  Haploesthes A. Gray -- accepted -- false broomweed
  Haploesthes greggii A. Gray -- accepted -- false broomweed
  Haploesthes greggii var. greggii A. Gray -- accepted
  Haplopappus acaulis (Nutt.) A. Gray -- not accepted
  Haplopappus alpigenus Torr. & A. Gray -- not accepted
  Haplopappus apargioides A. Gray -- not accepted
  Haplopappus arborescens (A. Gray) H.M. Hall -- not accepted
  Haplopappus armerioides (Nutt.) A. Gray -- not accepted
  Haplopappus aureus A. Gray -- not accepted
  Haplopappus blephariphyllus A. Gray -- not accepted
  Haplopappus bloomeri A. Gray -- not accepted
  Haplopappus bloomeri ssp. sonnei (A. Gray) H.M. Hall -- not accepted
  Haplopappus bloomeri var. angustatus A. Gray -- not accepted
  Haplopappus bloomeri var. greenei (A. Gray) Cronquist -- not accepted
  Haplopappus bloomeri var. sonnei (A. Gray) Greene -- not accepted
  Haplopappus brandegeei A. Gray -- not accepted
  Haplopappus canus (A. Gray) S.F. Blake -- not accepted
  Haplopappus carthamoides (Hook.) A. Gray -- not accepted
  Haplopappus carthamoides ssp. cusickii (A. Gray) H.M. Hall -- not accepted
  Haplopappus carthamoides var. cusickii A. Gray -- not accepted
  Haplopappus carthamoides var. maximus A. Gray -- not accepted
  Haplopappus coloradoensis (A. Gray) R.L. Hartm. ex Dorn -- not accepted
  Haplopappus cooperi (A. Gray) H.M. Hall -- not accepted
  Haplopappus coulteri Harv. & A. Gray ex A. Gray -- not accepted
  Haplopappus croceus A. Gray -- not accepted
  Haplopappus cuneatus A. Gray -- not accepted
  Haplopappus cuneatus var. spathulatus (A. Gray) S.F. Blake ex Munz -- not accepted
  Haplopappus divaricatus (Nutt.) A. Gray -- not accepted
  Haplopappus divaricatus var. hookerianus (Torr. & A. Gray) Waterf. -- not accepted
  Haplopappus drummondii (Torr. & A. Gray) S.F. Blake -- not accepted
  Haplopappus engelmannii (A. Gray) H.M. Hall -- not accepted
  Haplopappus fremontii (A. Gray) Greene -- not accepted
  Haplopappus fremontii ssp. wardii (A. Gray) H.M. Hall -- not accepted
  Haplopappus gracilis (Nutt.) A. Gray -- not accepted
  Haplopappus greenei A. Gray -- not accepted
  Haplopappus greenei var. mollis A. Gray -- not accepted
  Haplopappus hallii A. Gray -- not accepted
  Haplopappus heterophyllus (A. Gray) S.F. Blake -- not accepted
  Haplopappus hirtus A. Gray -- not accepted
  Haplopappus integrifolius Porter ex A. Gray -- not accepted
  Haplopappus lanceolatus (Hook.) Torr. & A. Gray -- not accepted
  Haplopappus lanceolatus var. lanceolatus (Hook.) Torr. & A. Gray -- not accepted
  Haplopappus lanceolatus var. tenuicaulis (D.C. Eaton) A. Gray -- not accepted
  Haplopappus lanuginosus A. Gray -- not accepted
  Haplopappus laricifolius A. Gray -- not accepted
  Haplopappus lyallii A. Gray -- not accepted
  Haplopappus macronema (Nutt.) A. Gray -- not accepted
  Haplopappus multicaulis (Nutt.) A. Gray -- not accepted
  Haplopappus nuttallii Torr. & A. Gray -- not accepted
  Haplopappus palmeri A. Gray -- not accepted
  Haplopappus paniculatus var. virgatus A. Gray -- not accepted
  Haplopappus parryi A. Gray -- not accepted
  Haplopappus pinifolius A. Gray -- not accepted
  Haplopappus pluriflorus (Torr. & A. Gray) H.M. Hall -- not accepted
  Haplopappus pygmaeus (Torr. & A. Gray) A. Gray -- not accepted
  Haplopappus racemosus var. glomerellus (Nutt.) A. Gray -- not accepted
  Haplopappus resinosus (Nutt.) A. Gray -- not accepted
  Haplopappus spinulosus var. canescens A. Gray -- not accepted
  Haplopappus spinulosus var. glaber A. Gray -- not accepted
  Haplopappus stenophyllus A. Gray -- not accepted
  Haplopappus suffruticosus (Nutt.) A. Gray -- not accepted
  Haplopappus uniflorus (Hook.) Torr. & A. Gray -- not accepted
  Haplopappus uniflorus ssp. howellii (A. Gray) H.M. Hall -- not accepted
  Haplopappus uniflorus var. howellii (A. Gray) M. Peck -- not accepted
  Haplopappus uniflorus var. uniflorus (Hook.) Torr. & A. Gray -- not accepted
  Haplopappus wardii (A. Gray) Dorn -- not accepted
  Haplopappus watsonii A. Gray -- not accepted
  Haplopappus whitneyi A. Gray -- not accepted
  Haplopappus whitneyi var. whitneyi A. Gray -- not accepted
  Haplostachys (A. Gray) Hillebr. -- accepted
  Haplostachys haplostachya (A. Gray) H. St. John -- accepted -- honohono
  Haplostachys truncata (A. Gray) Hillebr. -- accepted -- Maui islandmint
  Harbouria trachypleura (A. Gray) J.M. Coult. & Rose -- accepted -- whiskbroom parsley
  Harpagonella A. Gray -- accepted -- grapplinghook
  Harpagonella palmeri A. Gray -- accepted -- Palmer's grappling-hook, Palmer's grapplinghook
  Harpagonella palmeri var. palmeri A. Gray -- accepted -- Palmer's grapplinghook
  Hartwrightia A. Gray ex S. Watson -- accepted -- hartwrightia
  Hartwrightia floridana A. Gray ex S. Watson -- accepted -- Florida hartwrightia
  Hazardia cana (A. Gray) Greene -- accepted -- island hazardia
  Hazardia orcuttii (A. Gray) Greene -- accepted -- Orcutt's bristleweed, Orcutt's hazardia
  Hazardia whitneyi (A. Gray) Greene -- accepted -- Whitney's bristleweed
  Hazardia whitneyi var. whitneyi (A. Gray) Greene -- accepted -- Whitney's bristleweed
  Hecastocleis A. Gray -- accepted -- hecastocleis
  Hecastocleis shockleyi A. Gray -- accepted -- prickleleaf
  Hedeoma drummondii var. reverchonii A. Gray -- not accepted
  Hedeoma glabrescens (A. Gray) Briq. -- not accepted
  Hedeoma graveolens Chapm. ex A. Gray -- not accepted -- mock pennyroyal
  Hedeoma hyssopifolia A. Gray -- accepted -- aromatic false pennyroyal, falsepennyroyal, mock pennyroyal
  Hedeoma hyssopifolium A. Gray -- not accepted
  Hedeoma oblongifolia (A. Gray) A. Heller -- accepted -- false pennyroyal, falsepennyroyal, oblongleaf false pennyroyal
  Hedeoma oblongifolium (A. Gray) A. Heller -- not accepted
  Hedeoma piperita var. oblongifolia A. Gray -- not accepted
  Hedeoma reverchonii (A. Gray) A. Gray -- accepted -- Reverchon's false pennyroyal, Reverchon's falsepennyroyal
  Hedeoma reverchonii var. reverchonii (A. Gray) A. Gray -- accepted -- Reverchon's false pennyroyal, Reverchon's falsepennyroyal
  Hedeoma thymoides A. Gray -- not accepted
  Hedeoma thymoides var. oblongifolia (A. Gray) A. Gray -- not accepted
  Hedosyne ambrosiifolia (A. Gray) Strother -- accepted -- ragged marsh-elder
  Hedyotis acerosa A. Gray -- not accepted
  Hedyotis acerosa var. polypremoides (A. Gray) W.H. Lewis -- not accepted
  Hedyotis caerulea var. minor (Michx.) Torr. & A. Gray -- not accepted
  Hedyotis glaucifolia (A. Gray) Fosberg -- not accepted
  Hedyotis greenei (A. Gray) W.H. Lewis -- not accepted -- Greene's star-violet, Greene's starviolet
  Hedyotis halei Torr. & A. Gray -- not accepted
  Hedyotis humifusa A. Gray -- not accepted
  Hedyotis longifolia var. tenuifolia (Nutt.) Torr. & A. Gray -- not accepted
  Hedyotis minima (Beck) Torr. & A. Gray -- not accepted
  Hedyotis nigricans var. parviflora (A. Gray) W.H. Lewis -- not accepted
  Hedyotis nigricans var. rigidiuscula (A. Gray) Shinners -- not accepted
  Hedyotis parvula (A. Gray) Fosberg -- not accepted -- rockface starviolet
  Hedyotis polypremoides (A. Gray) Shinners -- not accepted
  Hedyotis purpurea (L.) Torr. & A. Gray -- not accepted
  Hedyotis purpurea var. calycosa (A. Gray) Fosberg -- not accepted
  Hedyotis rubra (Cav.) A. Gray -- not accepted
  Hedyotis stenophylla var. parviflora A. Gray -- not accepted
  Hedyotis subviscosa (C. Wright ex A. Gray) Shinners -- not accepted
  Hedyotis wrightii (A. Gray) Fosberg -- not accepted
  Heimia longipes (A. Gray) Cory -- not accepted
  Helenium amarum var. badium (A. Gray ex S. Watson) Waterf. -- accepted -- basin sneezeweed, yellowdicks
  Helenium amphilobum A. Gray -- not accepted
  Helenium autumnale var. canaliculatum (Lam.) Torr. & A. Gray -- not accepted
  Helenium autumnale var. grandiflorum (Nutt.) Torr. & A. Gray -- not accepted -- fall sneezeweed
  Helenium badium (A. Gray ex S. Watson) Greene -- not accepted
  Helenium bigelovii A. Gray -- accepted -- Bigelow's sneezeweed
  Helenium bolanderi A. Gray -- accepted -- coastal sneezeweed
  Helenium curtisii A. Gray -- not accepted
  Helenium elegans var. amphilobum (A. Gray) Bierner -- accepted -- pretty sneezeweed
  Helenium hoopesii A. Gray -- not accepted
  Helenium incisum (Torr. & A. Gray) Alph. Wood -- not accepted
  Helenium lanciniatum A. Gray -- accepted
  Helenium microcephalum var. ooclinium (A. Gray) Bierner -- accepted -- smallhead sneezeweed
  Helenium nuttallii A. Gray -- not accepted
  Helenium ooclinium A. Gray -- not accepted
  Helenium tenuifolium var. badium A. Gray ex S. Watson -- not accepted
  Helenium thurberi A. Gray -- accepted -- Thurber's sneezeweed
  Helianthella Torr. & A. Gray -- accepted -- helianthella
  Helianthella californica A. Gray -- accepted -- California helianthella
  Helianthella californica ssp. californica A. Gray -- accepted -- California helianthella
  Helianthella californica var. californica A. Gray -- not accepted -- California helianthella
  Helianthella grandiflora Torr. & A. Gray -- not accepted
  Helianthella microcephala (A. Gray) A. Gray -- accepted -- purpledisk helianthella, small-head dwarf-sunflower
  Helianthella parryi A. Gray -- accepted -- Parry's dwarf-sunflower, Parry's dwarfsunflower
  Helianthella pringlei A. Gray -- not accepted
  Helianthella quinquenervis (Hook.) A. Gray -- accepted -- fivenerve helianthella, nodding dwarf-sunflower, nodding helianthella
  Helianthella tenuifolia Torr. & A. Gray -- not accepted
  Helianthella uniflora (Nutt.) Torr. & A. Gray -- accepted -- oneflower helianthella
  Helianthella uniflora var. douglasii (Torr. & A. Gray) W.A. Weber -- not accepted -- Douglas' helianthella
  Helianthella uniflora var. uniflora (Nutt.) Torr. & A. Gray -- not accepted -- oneflower helianthella
  Helianthemum capitatum Nutt. ex Engelm. & A. Gray -- not accepted
  Helianthemum scoparium Nutt. ex Torr. & A. Gray -- accepted -- Bisbee Peak rushrose
  Helianthus argophyllis Torr. & A. Gray -- not accepted
  Helianthus argophyllus Torr. & A. Gray -- accepted -- silverleaf sunflower
  Helianthus bolanderi A. Gray -- accepted -- serpentine sunflower
  Helianthus canescens (A. Gray) S. Watson -- not accepted
  Helianthus cinereus var. sullivantii Torr. & A. Gray -- not accepted
  Helianthus cucumerifolius Torr. & A. Gray -- not accepted
  Helianthus cusickii A. Gray -- accepted -- Cusick's sunflower
  Helianthus debilis ssp. cucumerifolius (Torr. & A. Gray) Heiser -- accepted -- cucumberleaf sunflower
  Helianthus debilis ssp. praecox (Engelm. & A. Gray) Heiser -- not accepted
  Helianthus debilis var. cucumerifolius (Torr. & A. Gray) A. Gray -- not accepted
  Helianthus exilis A. Gray -- accepted -- serpentine sunflower
  Helianthus floridanus A. Gray ex Chapm. -- accepted -- Florida sunflower
  Helianthus gracilentus A. Gray -- accepted -- slender sunflower
  Helianthus grosseserratus var. hypoleucus A. Gray -- not accepted
  Helianthus hirsutus var. stenophyllus Torr. & A. Gray -- not accepted
  Helianthus hirsutus var. trachyphyllus Torr. & A. Gray -- not accepted
  Helianthus laciniatus A. Gray -- accepted -- alkali sunflower
  Helianthus laevigatus Torr. & A. Gray -- accepted -- smooth sunflower
  Helianthus microcephalus Torr. & A. Gray -- accepted -- small woodland sunflower
  Helianthus niveus ssp. canescens (A. Gray) Heiser -- not accepted -- showy sunflower
  Helianthus niveus ssp. tephrodes (A. Gray) Heiser -- accepted -- Algodones sunflower
  Helianthus nuttallii Torr. & A. Gray -- accepted -- Nuttall's sunflower
  Helianthus nuttallii ssp. nuttallii Torr. & A. Gray -- accepted -- Nuttall's sunflower
  Helianthus nuttallii ssp. parishii (A. Gray) Heiser -- accepted -- Parish's sunflower
  Helianthus occidentalis ssp. plantagineus (Torr. & A. Gray) Shinners -- accepted -- fewleaf sunflower, Gewleaf sunflower
  Helianthus occidentalis var. dowellianus (M.A. Curtis) Torr. & A. Gray -- not accepted
  Helianthus occidentalis var. plantagineus Torr. & A. Gray -- not accepted
  Helianthus parishii A. Gray -- not accepted
  Helianthus petiolaris var. canescens A. Gray -- not accepted
  Helianthus porteri (A. Gray) Pruski -- accepted -- Porter's sunflower
  Helianthus praecox Engelm. & A. Gray -- accepted -- Texas sunflower
  Helianthus praecox ssp. praecox Engelm. & A. Gray -- accepted -- Texas sunflower
  Helianthus radula (Pursh) Torr. & A. Gray -- accepted -- rayless sunflower, stiff sunflower
  Helianthus schweinitzii Torr. & A. Gray -- accepted -- Schweinitz's sunflower
  Helianthus stenophyllus (Torr. & A. Gray) E.E. Watson -- not accepted
  Helianthus tephrodes A. Gray -- not accepted
  Helianthus tuberosus var. subcanescens A. Gray -- not accepted
  Helianthus X ambiguus (A. Gray) Britton (pro sp.) -- accepted -- ambiguous sunflower
  Helianthus X cinereus Torr. & A. Gray (pro sp.) -- accepted -- sunflower
  Helietta parvifolia (A. Gray ex Hemsl.) Benth. -- accepted -- barreta
  Heliomeris hispida (A. Gray) Cockerell -- accepted -- hairy falsegoldeneye, rough false goldeneye
  Heliomeris porteri (A. Gray) Cockerell -- not accepted
  Heliomeris tenuifolia A. Gray -- not accepted
  Heliopsis parvifolia A. Gray -- accepted -- mountain oxeye
  Heliotropium anomalum var. argenteum A. Gray -- accepted -- Polynesian heliotrope
  Heliotropium confertifolium (Torr.) Torr. ex A. Gray -- accepted -- leafy heliotrope
  Heliotropium convolvulaceum (Nutt.) A. Gray -- not accepted -- bindweed heliotrope, phlox heliotrope, wide-flower heliotrope
  Heliotropium convolvulaceum var. convolvulaceum (Nutt.) A. Gray -- not accepted -- phlox heliotrope
  Heliotropium glabriusculum (Torr.) A. Gray -- accepted -- greeneye heliotrope
  Hemicarpha occidentalis A. Gray -- not accepted
  Hemitomes A. Gray -- accepted -- coneplant, gnome plant
  Hemitomes congestum A. Gray -- accepted -- coneplant, gnome plant
  Hemizonella (A. Gray) A. Gray -- accepted
  Hemizonella minima (A. Gray) A. Gray -- accepted -- opposite-leaved tarweed
  Hemizonia corymbosa (DC.) Torr. & A. Gray -- not accepted -- coastal tarweed
  Hemizonia corymbosa ssp. corymbosa (DC.) Torr. & A. Gray -- not accepted -- coastal tarweed
  Hemizonia douglasii A. Gray -- not accepted
  Hemizonia fasciculata (DC.) Torr. & A. Gray -- not accepted -- clustered tarweed
  Hemizonia fitchii A. Gray -- not accepted -- Fitch's tarweed
  Hemizonia floribunda A. Gray -- not accepted -- Tecate tarweed
  Hemizonia fremontii (A. Gray) A. Gray -- not accepted
  Hemizonia mollis (A. Gray) A. Gray -- not accepted
  Hemizonia multiglandulosa var. sparsa A. Gray -- not accepted
  Hemizonia paniculata A. Gray -- not accepted -- San Diego tarweed
  Hemizonia paniculata var. paniculata A. Gray -- not accepted
  Hemizonia pauciflora (A. Gray) A. Gray -- not accepted
  Hemizonia pugens (Hook. & Arn.) Torr. & A. Gray -- not accepted
  Hemizonia pugens var. pugens (Hook. & Arn.) Torr. & A. Gray -- not accepted
  Hemizonia pungens (Hook. & Arn.) Torr. & A. Gray -- not accepted -- common spikeweed, common tarweed, spikeweed
  Hemizonia pungens ssp. pungens (Hook. & Arn.) Torr. & A. Gray -- not accepted -- common tarweed, spikeweed
  Hemizonia tenella (Nutt.) A. Gray -- not accepted
  Hemizonia truncata (DC.) A. Gray -- not accepted
  Hermannia texana A. Gray -- accepted -- Texas burstwort, Texas hermannia
  Hesperevax (A. Gray) A. Gray -- accepted -- dwarf-cudweed
  Hesperevax caulescens (Benth.) A. Gray -- accepted -- dwarf dwarf-cudweed
  Hesperevax sparsiflora (A. Gray) Greene -- accepted -- erect dwarf-cudweed
  Hesperevax sparsiflora var. brevifolia (A. Gray) Morefield -- accepted -- shortleaf dwarf-cudweed
  Hesperevax sparsiflora var. sparsiflora (A. Gray) Greene -- accepted -- erect dwarf-cudweed
  Hesperidanthus linearifolius (A. Gray) Rydb. -- accepted -- slimleaf plainsmustard
  Hesperocallis A. Gray -- accepted -- desert lily
  Hesperocallis undulata A. Gray -- accepted -- desert lily
  Hesperodoria hallii (A. Gray) Greene -- not accepted
  Hesperolinon (A. Gray) Small -- accepted -- dwarf-flax
  Hesperolinon adenophyllum (A. Gray) Small -- accepted -- glandular dwarf-flax
  Hesperolinon breweri (A. Gray) Small -- accepted -- Brewer's dwarf-flax
  Hesperolinon congestum (A. Gray) Small -- accepted -- Marin dwarf-flax
  Hesperolinon micranthum (A. Gray) Small -- accepted -- smallflower dwarf-flax
  Hesperolinon spergulinum (A. Gray) Small -- accepted -- slender dwarf-flax
  Hesperomannia A. Gray -- accepted -- island-aster
  Hesperomannia arborescens A. Gray -- accepted -- Lanai island-aster
  Hesperomannia arborescens var. arborescens A. Gray -- not accepted
  Hesperonia bigelovii (A. Gray) Standl. -- not accepted
  Heterotheca bolanderi (A. Gray) V.L. Harms -- not accepted
  Heterotheca breweri (A. Gray) Shinners -- not accepted
  Heterotheca oligantha (Chapm. ex Torr. & A. Gray) V.L. Harms -- not accepted
  Heterotheca oregona var. scaberrima (A. Gray) Semple -- accepted -- Oregon false goldenaster
  Heterotheca scabrella (Torr. & A. Gray) V.L. Harms -- not accepted
  Heterotheca sessiliflora ssp. bolanderi (A. Gray) Semple -- accepted -- sessileflower false goldenaster
  Heterotheca stenophylla (A. Gray) Shinners -- accepted -- stiffleaf false goldenaster, stiffleaf falsegoldenaster
  Heterotheca stenophylla var. stenophylla (A. Gray) Shinners -- accepted -- stiffleaf false goldenaster
  Heterotheca villosa var. nana (A. Gray) Semple -- accepted -- hairy false goldenaster
  Heterotheca viscida (A. Gray) V.L. Harms -- accepted -- cliff false goldenaster, cliff falsegoldenaster
  Heuchera curtisii Torr. & A. Gray ex A. Gray -- not accepted
  Heuchera cylindrica var. glabella (Torr. & A. Gray) Wheelock -- not accepted -- beautiful alumroot
  Heuchera cylindrica var. ovalifolia (Torr. & A. Gray) Wheelock -- not accepted
  Heuchera glabella Torr. & A. Gray -- not accepted
  Heuchera hallii A. Gray -- accepted -- Front Range alumroot
  Heuchera ovalifolia Torr. & A. Gray -- not accepted
  Heuchera parvifolia Nutt. ex Torr. & A. Gray -- accepted -- common alumroot, little-leaf alumroot, littleleaf alumroot
  Heuchera parvifolia var. parvifolia Nutt. ex Torr. & A. Gray -- not accepted -- littleleaf alumroot
  Hibiscus arnottianus A. Gray -- accepted -- white rosemallow
  Hibiscus arnottianus ssp. arnottianus A. Gray -- accepted -- white rosemallow
  Hibiscus brackenridgei A. Gray -- accepted -- Brackenridge's rosemallow, ma'o hau hele
  Hibiscus brackenridgei ssp. brackenridgei A. Gray -- accepted -- Brackenridge's rosemallow
  Hibiscus cardiophyllus A. Gray -- not accepted
  Hibiscus coulteri Harv. ex A. Gray -- accepted -- Coulter's hibiscus, desert rosemallow
  Hibiscus denudatus var. involucellatus A. Gray -- not accepted
  Hieracium argutum var. parishii (A. Gray) Jeps. -- not accepted
  Hieracium bolanderi A. Gray -- accepted -- Bolander's hawkweed
  Hieracium cynoglossoides var. nudicaule A. Gray -- not accepted
  Hieracium fendleri var. discolor A. Gray -- not accepted -- yellow hawkweed
  Hieracium fendleri var. mogollense A. Gray -- not accepted -- Mogollon hawkweed
  Hieracium gracile var. detonsum (A. Gray) A. Gray -- not accepted -- low alpine hawkweed
  Hieracium greenei A. Gray -- accepted -- Greene's hawkweed
  Hieracium lemmonii A. Gray -- not accepted -- Lemmon's hawkweed
  Hieracium nudicaule (A. Gray) A. Heller -- accepted -- Scouler's woollyweed
  Hieracium pringlei A. Gray -- accepted -- Pringle's hawkweed
  Hieracium scouleri var. nudicaule (A. Gray) Cronquist -- not accepted -- Scouler's woollyweed, woollyweed
  Hieracium triste var. gracile (Hook.) A. Gray -- not accepted
  Hieracium wrighti (A. Gray) Keck -- not accepted
  Hieracium wrightii (A. Gray) B.L. Rob. & Greenm. -- not accepted -- roughstem hawkweed
  Himantostemma pringlei A. Gray -- not accepted
  Hirculus serpyllifolius ssp. chrysanthus (A. Gray) W.A. Weber -- not accepted
  Hoffmannseggia brachycarpa A. Gray -- not accepted
  Hoffmannseggia caudata A. Gray -- not accepted
  Hoffmannseggia densiflora var. demissa (A. Gray) Fisher -- not accepted
  Hoffmannseggia drepanocarpa A. Gray -- accepted -- sicklepod holdback
  Hoffmannseggia drummondii Torr. & A. Gray -- accepted -- dwarf nicker
  Hoffmannseggia jamesii Torr. & A. Gray -- not accepted
  Hoffmannseggia melanosticta (S. Schauer) A. Gray -- not accepted
  Hoffmanseggia drepanocarpa A. Gray -- not accepted
  Hofmeisteria pluriseta A. Gray -- not accepted
  Holacantha A. Gray -- accepted
  Holacantha emoryi A. Gray -- not accepted
  Holcophacos distortus (Torr. & A. Gray) Rydb. -- not accepted
  Holocarpha virgata (A. Gray) D.D. Keck -- accepted -- yellowflower tarweed
  Holocarpha virgata ssp. virgata (A. Gray) D.D. Keck -- accepted -- yellowflower tarweed
  Honckenya oblongifolia Torr. & A. Gray -- not accepted
  Horkelia bolanderi A. Gray -- accepted -- Bolander's horkelia, border horkelia
  Horkelia bolanderi ssp. bolanderi A. Gray -- not accepted -- Bolanders horkelia
  Horkelia californica var. sericea A. Gray -- not accepted
  Horkelia cuneata ssp. sericea (A. Gray) D.D. Keck -- not accepted -- wedge-leaved horkelia, wedgeleaf horkelia
  Horkelia cuneata var. sericea (A. Gray) Ertter & Reveal -- accepted -- wedgeleaf horkelia
  Horkelia sericea (A. Gray) Rydb. -- not accepted
  Horkelia tenuiloba (Torr.) A. Gray -- accepted -- Santa Rosa horkelia
  Horsfordia A. Gray -- accepted -- velvet mallow, velvetmallow
  Horsfordia alata (S. Watson) A. Gray -- accepted -- big feltplant, pink velvetmallow
  Horsfordia newberryi (S. Watson) A. Gray -- accepted -- Newberry's velvetmallow, yellow feltplant
  Hosackia argophylla A. Gray -- not accepted
  Hosackia fremontii (A. Gray) Abrams -- not accepted
  Hosackia puberula var. nana A. Gray -- not accepted
  Hosackia subpinnata auct. non (Lag.) Torr. & A. Gray -- not accepted
  Hosackia torreyi A. Gray -- not accepted
  Hosackia wrightii A. Gray -- not accepted
  Houstonia acerosa (A. Gray) Benth. & Hook. f. -- accepted -- needleleaf bluet
  Houstonia acerosa ssp. acerosa (A. Gray) A. Gray ex Benth. & Hook. f. -- not accepted -- needleleaf bluet
  Houstonia acerosa ssp. polypremoides (A. Gray) Terrell -- not accepted -- needleleaf bluet
  Houstonia acerosa var. acerosa (A. Gray) A. Gray ex Benth. & Hook. f. -- accepted -- needleleaf bluet
  Houstonia acerosa var. polypremoides (A. Gray) Terrell -- accepted
  Houstonia angustifolia var. filifolia (Chapm.) A. Gray -- not accepted
  Houstonia angustifolia var. rigidiuscula A. Gray -- not accepted
  Houstonia calycosa (A. Gray) C. Mohr -- not accepted
  Houstonia fasciculata A. Gray -- not accepted
  Houstonia greenei (A. Gray) Terrell -- accepted
  Houstonia humifusa (A. Gray) A. Gray -- accepted -- mat bluets, matted bluet
  Houstonia polypremoides A. Gray -- not accepted
  Houstonia purpurea var. calycosa A. Gray -- accepted -- Venus' pride
  Houstonia purpurea var. tenuifolia (Nutt.) A. Gray -- not accepted
  Houstonia rigidiuscula (A. Gray) Wooton & Standl. -- not accepted
  Houstonia subviscosa (C. Wright ex A. Gray) A. Gray -- accepted -- nodding bluet
  Houstonia wrightii A. Gray -- accepted -- pygmy bluet
  Howellia A. Gray -- accepted
  Howellia aquatilis A. Gray -- accepted -- water howellia
  Hulsea Torr. & A. Gray -- accepted -- alpinegold, hulsea
  Hulsea algida A. Gray -- accepted -- alpine hulsea, Pacific hulsea
  Hulsea brevifolia A. Gray -- accepted -- shortleaf alpinegold
  Hulsea californica Torr. & A. Gray -- accepted -- San Diego alpinegold
  Hulsea heterochroma A. Gray -- accepted -- redray alpinegold, redray hulsea
  Hulsea larsenii (A. Gray) Rydb. -- not accepted
  Hulsea nana A. Gray -- accepted -- dwarf alpinegold
  Hulsea nana var. larsenii A. Gray -- not accepted
  Hulsea parryi A. Gray -- not accepted
  Hulsea vestita A. Gray -- accepted -- pumice alpinegold, pumice hulsea
  Hulsea vestita ssp. parryi (A. Gray) Wilken -- accepted -- Parry's alpinegold
  Hulsea vestita ssp. pygmaea (A. Gray) Wilken -- accepted -- pygmy alpinegold
  Hulsea vestita ssp. vestita A. Gray -- accepted -- pumice alpinegold, pumice hulsea
  Hulsea vestita var. pygmaea A. Gray -- not accepted
  Hybanthus verticillatus var. platyphyllus (A. Gray) Cory & H.B. Parks -- not accepted -- babyslippers
  Hydrangea arborescens var. oblonga Torr. & A. Gray -- not accepted
  Hydrangea arborescens var. sterilis Torr. & A. Gray -- not accepted
  Hydrolea affinis A. Gray -- not accepted
  Hydrophila drummondii sensu (Torr. & A. Gray) House -- not accepted
  Hydrophila drummondii (Torr. & A. Gray) House -- not accepted
  Hydrophyllum fendleri (A. Gray) A. Heller -- accepted -- Fendler's waterleaf
  Hydrophyllum fendleri var. fendleri (A. Gray) A. Heller -- accepted -- Fendler's waterleaf
  Hydrophyllum occidentale (S. Watson) A. Gray -- accepted -- squaw-lettuce, western waterleaf
  Hydrophyllum occidentale var. watsonii A. Gray -- not accepted
  Hymenatherum neomexicanum A. Gray -- not accepted
  Hymenatherum tagetoides (Torr. & A. Gray) A. Gray -- not accepted
  Hymenoclea Torr. & A. Gray ex A. Gray -- accepted -- burrobrush
  Hymenoclea monogyla Torr. & A. Gray -- not accepted
  Hymenoclea monogyra Torr. & A. Gray -- not accepted -- cheeseweed burrobrush, singlewhorl burrobrush, singlewhorl burrobush
  Hymenoclea salsola Torr. & A. Gray -- not accepted -- burrobrush, white burrobrush
  Hymenoclea salsola var. salsola Torr. & A. Gray -- not accepted -- burrobrush, white burrobrush
  Hymenopappus corymbosus Torr. & A. Gray -- not accepted
  Hymenopappus flavescens A. Gray -- accepted -- collegeflower, yellow woollywhite, yellow woolywhite
  Hymenopappus flavescens var. canotomentosus A. Gray -- accepted -- college flower, collegeflower
  Hymenopappus flavescens var. flavescens A. Gray -- accepted -- collegeflower
  Hymenopappus mexicanus A. Gray -- accepted -- Mexican woollywhite
  Hymenopappus newberryi (A. Gray) I.M. Johnst. -- accepted -- Newberry's hymenopappus, Newberry's woollywhite
  Hymenopappus scabiosaeus var. corymbosus (Torr. & A. Gray) B.L. Turner -- accepted -- Carolina woollywhite
  Hymenothrix A. Gray -- accepted -- hymenothrix, thimblehead
  Hymenothrix wislizeni A. Gray -- accepted -- Trans-Pecos thimblehead
  Hymenothrix wislizenii A. Gray -- not accepted
  Hymenothrix wrightii A. Gray -- accepted -- Wright's thimblehead
  Hymenoxys acaulis var. glabra (A. Gray) K.F. Parker -- not accepted
  Hymenoxys ambigens var. floribunda (A. Gray) W.L. Wagner -- accepted -- Apache Pass rubberweed
  Hymenoxys argentea (A. Gray) K.F. Parker -- not accepted
  Hymenoxys bigelovii (A. Gray) K.F. Parker -- accepted -- Bigelow's rubberweed
  Hymenoxys brandegeei Porter ex A. Gray -- accepted -- Brandegee's four-nerve daisy, Brandegee's hymenoxys
  Hymenoxys cooperi (A. Gray) Cockerell -- accepted -- Cooper's hymenoxys, Cooper's rubberweed
  Hymenoxys cooperi var. cooperi (A. Gray) Cockerell -- not accepted -- Cooper's frostmat, Cooper's hymenoxys, Cooper's rubberweed
  Hymenoxys depressa (Torr. & A. Gray ex A. Gray) S.L. Welsh & Reveal -- not accepted
  Hymenoxys grandiflora (Torr. & A. Gray ex A. Gray) K.F. Parker -- accepted -- graylocks four-nerve daisy, graylocks hymenoxys
  Hymenoxys hoopesii (A. Gray) Bierner -- accepted -- orange sneezeweed, owl's-claws, owlsclaws, sneezeweed
  Hymenoxys microcephala (A. Gray) Bierner -- not accepted -- Apache Pass false rubbervine, Apache Pass rubberweed
  Hymenoxys richardsonii var. floribunda (A. Gray) K.F. Parker -- accepted -- Colorado rubberweed
  Hymenoxys rusbyi (A. Gray) Cockerell -- accepted -- Rusby's rubberweed
  Hymenoxys vaseyi (A. Gray) Cockerell -- accepted -- Vasey's rubberweed
  Hypericum canadense var. majus A. Gray -- not accepted
  Hypericum drummondii (Grev. & Hook.) Torr. & A. Gray -- accepted -- Drummond's St. Johnswort, nits and lice
  Hypericum gymnanthum Engelm. & A. Gray -- accepted -- claspingleaf St. Johnswort
  Hypericum majus (A. Gray) Britton -- accepted -- greater Canadian St. John's-wort, large St. Johnswort
  Hypericum microsepalum (Torr. & A. Gray) A. Gray ex S. Watson -- accepted -- flatwoods St. Johnswort
  Hypericum opacum Torr. & A. Gray -- not accepted
  Hypopitys fimbriata (A. Gray) Howell -- not accepted
  Hypoxis hirsuta var. leptocarpa (Engelm. & A. Gray) Brackett -- not accepted
  Hypoxis leptocarpa (Engelm. & A. Gray) Small -- not accepted
  Ibervillea lindheimeri (A. Gray) Greene -- accepted -- balsamgourd, Lindheimer's globeberry, Rio Grande globeberry
  Ibervillea tenuisecta (A. Gray) Small -- accepted -- deer-apples, slimlobe globeberry
  Ibidium vernale (Engelm. & A. Gray) House -- not accepted
  Ilex ambigua var. montana (Torr. & A. Gray ex A. Gray) H.E. Ahles -- not accepted
  Ilex ambigua var. monticola (A. Gray) Wunderlin & Poppleton -- not accepted
  Ilex amelanchier var. monticola (A. Gray) Alph. Wood -- not accepted
  Ilex glabra (L.) A. Gray -- accepted -- inkberry
  Ilex laevigata (Pursh) A. Gray -- accepted -- smooth winterberry
  Ilex montana Torr. & A. Gray ex A. Gray -- accepted -- mountain holly, mountain winterberry
  Ilex montana var. mollis (A. Gray) Britton -- not accepted
  Ilex monticola A. Gray -- not accepted
  Ilex verticillata (L.) A. Gray -- accepted -- common winterberry
  Ilex verticillata var. padifolia (Willd.) Torr. & A. Gray ex S. Watson -- not accepted
  Iliamna acerifolia (Nutt. ex Torr. & A. Gray) Greene -- not accepted
  Indigofera leptosepala Nutt. ex Torr. & A. Gray -- not accepted
  Indigofera miniata var. leptosepala (Nutt. ex Torr. & A. Gray) B.L. Turner -- not accepted -- western indigo
  Indigofera sphaerocarpa A. Gray -- accepted -- Sonoran indigo, Sonoran indigobush
  Iodanthus (Torr. & A. Gray) Steud. -- accepted
  Iodanthus hesperidioides (Torr. & A. Gray) A. Gray -- not accepted
  Ionactis stenomeres (A. Gray) Greene -- accepted -- Rocky Mountain aster
  Ipomoea barbatisepala A. Gray -- accepted -- canyon morning-glory, canyon morningglory
  Ipomoea cardiophylla A. Gray -- accepted -- heartleaf morning-glory, heartleaf morningglory
  Ipomoea coccinea var. hederifolia (L.) A. Gray -- not accepted
  Ipomoea cordatotriloba var. torreyana (A. Gray) D.F. Austin -- accepted -- cotton morningglory, Torrey's tievine
  Ipomoea cuneifolia A. Gray -- not accepted
  Ipomoea hederacea var. integriuscula A. Gray -- not accepted
  Ipomoea lemmonii A. Gray -- not accepted
  Ipomoea lindheimeri A. Gray -- accepted -- blue morningglory, Lindheimer's morning-glory, Lindheimer's morningglory
  Ipomoea plummerae A. Gray -- accepted -- Huachuca morningglory, Huachuca Mountain morning-glory, Huachuca Mountain morningglory
  Ipomoea plummerae var. cuneifolia (A. Gray) J.F. Macbr. -- not accepted -- Huachuca Mountain morning-glory, Huachuca Mountain morningglory
  Ipomoea plummerae var. plummerae A. Gray -- not accepted -- Huachuca Mountain morning-glory, Huachuca Mountain morningglory
  Ipomoea tenuiloba var. lemmonii (A. Gray) Yatsk. & C.T. Mason -- accepted -- Lemmon's morning-glory, spiderleaf
  Ipomoea thurberi A. Gray -- accepted -- Thurber's morning-glory, Thurber's morningglory
  Ipomoea trichocarpa var. torreyana (A. Gray) Shinners -- not accepted
  Ipomoea trifida var. torreyana A. Gray -- not accepted
  Ipomoea wrightii A. Gray -- accepted -- palmleaf morningglory, Wright's morning-glory, Wright's morningglory
  Ipomopsis aggregata ssp. attenuata (A. Gray) V.E. Grant & A.D. Grant -- accepted -- scarlet gilia
  Ipomopsis aggregata ssp. bridgesii (A. Gray) V.E. Grant & A.D. Grant -- accepted -- scarlet gilia
  Ipomopsis aggregata var. attenuata (A. Gray) Dorn -- not accepted
  Ipomopsis bridgesii (A. Gray) Wherry -- not accepted
  Ipomopsis depressa (M.E. Jones ex A. Gray) V.E. Grant -- not accepted -- depressed ipomopsis, depressed skyrocket
  Ipomopsis effusa (A. Gray) Moran -- accepted -- Baja California ipomopsis
  Ipomopsis gunnisonii (Torr. & A. Gray) V.E. Grant -- accepted -- sand-dune skyrocket, sanddune ipomopsis, sanddune skyrocket
  Ipomopsis harvardii (A. Gray) V.E. Grant -- not accepted
  Ipomopsis havardii (A. Gray) V.E. Grant -- accepted -- Havard's ipomopsis, Havard's skyrocket
  Ipomopsis macombii (Torr. ex A. Gray) V.E. Grant -- accepted -- Macomb's ipomopsis, Macomb's skyrocket
  Ipomopsis spicata ssp. capitata (A. Gray) V.E. Grant -- accepted -- spiked ipomopsis
  Ipomopsis stenothyrsa (A. Gray) W.A. Weber -- not accepted
  Ipomopsis teniufolia (A. Gray) V.E. Grant -- not accepted
  Ipomopsis tenuifolia (A. Gray) V.E. Grant -- accepted -- slender-leaf skyrocket, slenderleaf skyrocket
  Ipomopsis thurberi (Torr. ex A. Gray) V.E. Grant -- accepted -- El Paso skyrocket, Thurber skyrocket
  Ipomopsis wrightii (A. Gray) Gould ex Shinners -- accepted -- leafy skyrocket
  Isnardia spathulata (Torr. & A. Gray) Small -- not accepted
  Isocoma coronopifolia (A. Gray) Greene -- accepted -- common goldenbush, goldenweed
  Isocoma drummondii (Torr. & A. Gray) Greene -- accepted -- Drummond's goldenbush, Drummond's goldenweed, Drummond's jimmyweed
  Isocoma palmeri (A. Gray) Shinners -- not accepted
  Isocoma pluriflora (Torr. & A. Gray) Greene -- accepted -- rayless goldenrod, southern goldenbush, southern jimmyweed
  Isocoma wrightii (A. Gray) Rydb. -- not accepted
  Isodendrion A. Gray -- accepted
  Isodendrion laurifolium A. Gray -- accepted -- aupaka, rockcliff isodendrion
  Isodendrion longifolium A. Gray -- accepted -- aupaka, longleaf isodendrion
  Isodendrion pyrifolium A. Gray -- accepted -- Kula wahine noho, wahine noho kula
  Isopappus divaricatus (Nutt.) Torr. & A. Gray -- not accepted
  Isopappus hookerianus Torr. & A. Gray -- not accepted
  Isopyrum biternatum (Raf.) Torr. & A. Gray -- not accepted
  Isopyrum hallii A. Gray -- not accepted
  Isopyrum stipitatum A. Gray -- not accepted
  Iva ambrosiifolia (A. Gray) A. Gray -- not accepted -- rag sumpweed, ragged marsh-elder, ragged marshelder
  Iva ambrosiifolia var. ambrosiifolia (A. Gray) A. Gray -- not accepted
  Iva dealbata A. Gray -- not accepted -- woolly marsh-elder, woolly marshelder
  Iva hayesiana A. Gray -- accepted -- San Diego povertyweed
  Ivesia Torr. & A. Gray -- accepted -- mousetail
  Ivesia gordanii (Hook.) Torr. & A. Gray -- not accepted
  Ivesia gordonii (Hook.) Torr. & A. Gray -- accepted -- Gordon's ivesia
  Ivesia gordonii var. gordonii (Hook.) Torr. & A. Gray -- accepted -- Gordon's ivesia
  Ivesia gordonii var. pygmea (A. Gray) S. Watson -- not accepted -- Gordon's ivesia
  Ivesia gracilis Torr. & A. Gray -- not accepted
  Ivesia lycopodioides A. Gray -- accepted -- clubmoss ivesia, clubmoss mousetail
  Ivesia lycopodioides ssp. lycopodioides A. Gray -- not accepted -- clubmoss ivesia, clubmoss mousetail
  Ivesia lycopodioides var. lycopodioides A. Gray -- accepted -- clubmoss mousetail
  Ivesia muirii A. Gray -- accepted -- granite mousetail
  Ivesia pickeringii Torr. ex A. Gray -- accepted -- Pickering ivesia, silky mousetail
  Ivesia pygmaea A. Gray -- accepted -- dwarf ivesia, dwarf mousetail
  Ivesia santolinoides A. Gray -- accepted -- Sierra mousetail
  Ivesia unguiculata A. Gray -- accepted -- Yosemite mousetail
  Ivesia webberi A. Gray -- accepted -- Webber ivesia, Webber's ivesia, wire mousetail
  Ixeris stolonifera A. Gray -- accepted -- creeping lettuce
  Jacksonia tenuifolia (Torr. & A. Gray) Greene -- not accepted
  Jacobinia ovata A. Gray -- not accepted
  Jacquemontia ovalifolia ssp. sandwicensis (A. Gray) K.R. Robertson -- accepted -- oval-leaf clustervine
  Jacquemontia pringlei A. Gray -- accepted -- Pringle's clustervine
  Jacquemontia sandwicensis A. Gray -- not accepted
  Jamesia Torr. & A. Gray -- accepted -- cliffbush
  Jamesia americana Torr. & A. Gray -- accepted -- cliff Jamesia, cliffbush, fivepetal cliffbush
  Jamesia americana var. americana Torr. & A. Gray -- accepted -- fivepetal cliffbush
  Janusia gracilis A. Gray -- not accepted -- slender janusia
  Jaumea carnosa (Less.) A. Gray -- accepted -- marsh jaumea
  Jefea brevifolia (A. Gray) Strother -- accepted -- shorthorn zexmenia, shortleaf jefea
  Jensia yosemitana (Parry ex A. Gray) B.G. Baldw. -- accepted -- Yosemite tarweed
  Juncus debilis A. Gray -- accepted -- weak rush
  Justicia wrightii A. Gray -- accepted -- Wright's water-willow
  Kadua grandis A. Gray -- not accepted
  Kadua parvula A. Gray -- accepted
  Kallstroemia grandiflora Torr. ex A. Gray -- accepted -- Arizona poppy, orange caltrop
  Keckiella antirrhinoides ssp. microphylla (A. Gray) Straw -- accepted -- bush penstemon, snapdragon penstemon
  Keckiella antirrhinoides var. microphylla (A. Gray) N.H. Holmgren -- not accepted
  Keckiella lemmonii (A. Gray) Straw -- accepted -- bush beardtongue, Lemmon's keckiella
  Keckiella rothrockii (A. Gray) Straw -- accepted -- Rothrock's keckiella, Rothrock's penstemon
  Keckiella rothrockii ssp. rothrockii (A. Gray) Straw -- accepted -- Rothrock's keckiella, Rothrock's penstemon
  Keckiella rothrockii var. rothrockii (A. Gray) Straw -- not accepted
  Keckiella ternata (Torr. ex A. Gray) Straw -- accepted -- scarlet keckiella
  Keckiella ternata ssp. ternata (Torr. ex A. Gray) Straw -- accepted -- scarlet keckiella
  Keckiella ternata var. ternata (Torr. ex A. Gray) Straw -- not accepted
  Keerlia bellidifolia A. Gray & Engelm. -- not accepted
  Keerlia effusa A. Gray -- not accepted
  Koanophyllon palmeri (A. Gray) R.M. King & H. Rob. -- accepted -- Palmer's umbrella thoroughwort
  Koanophyllon solidaginifolium (A. Gray) R.M. King & H. Rob. -- accepted -- shrubby thoroughwort
  Koeleria cristata var. gracilis (Pers.) A. Gray -- not accepted
  Koellia albescens (Torr. & A. Gray) Kuntze -- not accepted
  Koellia clinopodioides (Torr. & A. Gray) Kuntze -- not accepted
  Koellia dubia (A. Gray) Small -- not accepted
  Koellia leptodon (A. Gray) Small -- not accepted
  Kopsiopsis strobilacea (A. Gray) Beck -- accepted -- California groundcone
  Kosteletzkya smilacifolia A. Gray -- not accepted
  Kosteletzkya virginica (L.) C. Presl ex A. Gray -- not accepted -- Virginia saltmarsh mallow, Virginia saltmarsh willow
  Krameria ramosissima (A. Gray) S. Watson -- accepted -- manystem ratany, trailing ratany
  Kraunhia macrostachya (Torr. & A. Gray) Small -- not accepted
  Krigia wrightii (A. Gray) K.L. Chambers ex Kim -- accepted -- Wright's dwarfdandelion
  Krynitzkia crassisepala (Torr. & A. Gray) A. Gray -- not accepted
  Krynitzkia jamesii (Torr.) A. Gray -- not accepted
  Krynitzkia utahensis A. Gray -- not accepted
  Kuhnia eupatorioides var. corymbulosa Torr. & A. Gray -- not accepted
  Kuhnia eupatorioides var. gracilis Torr. & A. Gray -- not accepted
  Kuhnia eupatorioides var. gracillima A. Gray -- not accepted
  Kuhnia shaffneri A. Gray -- not accepted
  Kumlienia hystricula (A. Gray) Greene -- not accepted -- waterfall false buttercup
  Kyhosia bolanderi (A. Gray) B.G. Baldw. -- accepted -- Bolander's madia
  Labordia fagraeoidea var. sessilis (A. Gray) Sherff -- not accepted
  Labordia sessilis A. Gray -- accepted -- thinfruit labordia
  Labordia tinifolia A. Gray -- accepted -- paleflower labordia
  Labordia tinifolia var. tinifolia A. Gray -- accepted -- paleflower labordia
  Lachnostoma arizonicum A. Gray -- not accepted
  Lacinaria acidota (Engelm. & A. Gray) Kuntze -- not accepted
  Lacinaria boykinii (Torr. & A. Gray) Kuntze -- not accepted
  Lacinaria chapmanii (Torr. & A. Gray) Kuntze -- not accepted
  Lacinaria garberi (A. Gray) Kuntze -- not accepted
  Lactuca canadensis var. integrifolia (Bigelow) Torr. & A. Gray -- not accepted
  Lactuca hirsuta var. albiflora (Torr. & A. Gray) Shinners -- not accepted -- hairy lettuce
  Lactuca spicata var. integrifolia (Torr. & A. Gray) Britton -- not accepted
  Lactuca stolonifera (A. Gray) Maxim. -- not accepted
  Laennecia coulteri (A. Gray) G.L. Nesom -- accepted -- annual horsetail, conyza, Coulter's horseweed
  Laennecia eriophylla (A. Gray) G.L. Nesom -- accepted -- Cochise marshtail
  Lagophylla glandulosa A. Gray -- accepted -- glandular hareleaf
  Lagophylla glandulosa ssp. glandulosa A. Gray -- not accepted -- glandular hareleaf
  Langloisia matthewsii (A. Gray) Greene -- accepted
  Langloisia punctata (A. Gray ex Coville) Goodd. -- not accepted
  Langloisia setosissima (Torr. & A. Gray ex Torr.) Greene -- accepted -- Great Basin langloisia, moth langloisia
  Langloisia setosissima ssp. punctata (A. Gray ex Coville) Timbrook -- accepted -- Great Basin langloisia
  Langloisia setosissima ssp. setosissima (Torr. & A. Gray ex Torr.) Greene -- accepted -- Great Basin langloisia
  Laphamia angustifolia A. Gray -- not accepted
  Laphamia angustifolia ssp. laciniata (A. Gray) Niles -- not accepted
  Laphamia bisetosa Torr. ex A. Gray -- not accepted
  Laphamia cinerea A. Gray -- not accepted
  Laphamia halimifolia A. Gray -- not accepted
  Laphamia halimifolia ssp. lindheimeri (A. Gray) Niles -- not accepted
  Laphamia palmeri A. Gray -- not accepted
  Laphamia rupestris A. Gray -- not accepted
  Laphamia stansburii A. Gray -- not accepted
  Laphamia stansburyi A. Gray -- not accepted
  Lapithea boykinii (A. Gray) Small -- not accepted
  Lappula americana (A. Gray) Rydb. -- not accepted
  Lappula deflexa ssp. americana (A. Gray) Hultén -- not accepted
  Lappula deflexa var. americana (A. Gray) Greene -- not accepted
  Lappula hispida (A. Gray) Greene -- not accepted
  Lappula occidentalis var. cupulata (A. Gray) Higgins -- accepted -- flat-spine sheepburr, flatspine stickseed
  Lappula redowskii var. cupulata (A. Gray) M.E. Jones -- not accepted
  Lasianthaea podocephala (A. Gray) K. Becker -- accepted -- San Pedro daisy
  Lasthenia californica ssp. macrantha (A. Gray) R. Chan -- accepted -- perennial goldfields
  Lasthenia chrysantha (Greene ex A. Gray) Greene -- accepted -- alkali sink goldfields
  Lasthenia debilis (Greene ex A. Gray) Ornduff -- accepted -- Greene's goldfields
  Lasthenia fremontii (Torr. ex A. Gray) Greene -- accepted -- Fremont's goldfields
  Lasthenia glabrata ssp. coulteri (A. Gray) Ornduff -- accepted -- Coulter's goldfields
  Lasthenia glabrata var. coulteri A. Gray -- not accepted
  Lasthenia leptalea (A. Gray) Ornduff -- accepted -- Salinas Valley goldfields
  Lasthenia macrantha (A. Gray) Greene -- not accepted -- perennial goldfields
  Lasthenia macrantha ssp. macrantha (A. Gray) Greene -- not accepted -- perennial goldfields
  Lasthenia maritima (A. Gray) Ornduff -- accepted -- seaside goldfields
  Lasthenia minor ssp. maritima (A. Gray) Ornduff -- not accepted
  Lasthenia minor var. maritima (A. Gray) Cronquist -- not accepted
  Lasthenia platycarpha (A. Gray) Greene -- accepted -- alkali goldfields
  Lathrocasis tenerrima (A. Gray) L.A. Johnson -- accepted -- delicate gilia
  Lathyrus palustris var. myrtifolius (Muhl. ex Willd.) A. Gray -- not accepted
  Lathyrus sulphureus W.H. Brewer ex A. Gray -- accepted -- snub pea, sulfur pea
  Lathyrus sulphureus var. sulphureus W.H. Brewer ex A. Gray -- accepted -- snub pea
  Lathyrus torreyi A. Gray -- accepted -- Torrey's pea
  Lavauxia brachycarpa (A. Gray) Britton -- not accepted
  Layia carnosa (Nutt.) Torr. & A. Gray -- accepted -- beach layia, beach tidytips
  Layia chrysanthemoides (DC.) A. Gray -- accepted -- smooth tidytips
  Layia fremontii (Torr. & A. Gray) A. Gray -- accepted -- Fremont's tidytips
  Layia jonesii A. Gray -- accepted -- Jones' tidytips
  Layia pentachaeta A. Gray -- accepted -- Sierra tidytips
  Layia pentachaeta ssp. pentachaeta A. Gray -- accepted -- Sierra tidytips
  Layia platyglossa (Fisch. & C.A. Mey.) A. Gray -- accepted -- coastal tidytips
  Layia platyglossa ssp. platyglossa (Fisch. & C.A. Mey.) A. Gray -- not accepted -- coastal tidytips
  Layia platyglossa var. breviseta A. Gray -- not accepted
  Leavenworthia stylosa A. Gray -- accepted -- cedar gladecress
  Leavenworthia torulosa A. Gray -- accepted -- necklace gladecress
  Lechea minor var. maritima (Legg. ex Britton, Sterns & Poggenb.) A. Gray -- not accepted
  Leiophyllum buxifolium var. prostratum (Loudon) A. Gray -- not accepted
  Lembertia congdonii (A. Gray) Greene -- not accepted -- San Joaquin woollythread, San Joaquin wooly-threads
  Lemmonia A. Gray -- not accepted
  Lemmonia californica A. Gray -- not accepted
  Lepachys columnaris (Pursh) Torr. & A. Gray -- not accepted
  Lepachys peduncularis Torr. & A. Gray -- not accepted
  Lepachys peduncularis var. picta A. Gray -- not accepted
  Lepachys pinnata (Vent.) Torr. & A. Gray -- not accepted
  Lepadena bicolor (Engelm. & A. Gray) Nieuwl. -- not accepted
  Lepechinia hastata (A. Gray) Epling -- accepted -- pakaha
  Lepidium acutidens (A. Gray) Howell -- accepted -- alkali pepperwort
  Lepidium alyssoides A. Gray -- accepted -- mesa pepperwort, southern pepperweed
  Lepidium alyssoides var. alyssoides A. Gray -- not accepted -- mesa pepperwort
  Lepidium dictyotum A. Gray -- accepted -- alkali pepperweed, net pepperweed
  Lepidium dictyotum var. acutidens A. Gray -- not accepted -- alkali pepperwort
  Lepidium dictyotum var. dictyotum A. Gray -- not accepted -- alkali pepperweed
  Lepidium lasiocarpum ssp. wrightii (A. Gray) Thell. -- accepted -- Wright's pepperweed
  Lepidium lasiocarpum var. wrightii (A. Gray) C.L. Hitchc. -- not accepted -- Wright's pepperweed
  Lepidium montanum ssp. alyssoides (A. Gray) C.L. Hitchc. -- not accepted
  Lepidium montanum var. alyssoides (A. Gray) M.E. Jones -- not accepted
  Lepidium oxycarpum Torr. & A. Gray -- accepted -- forked pepperweed
  Lepidium sordidum A. Gray -- accepted -- sordid pepperweed
  Lepidospartum (A. Gray) A. Gray -- accepted -- broomsage
  Lepidospartum squamatum (A. Gray) A. Gray -- accepted -- California broomsage, California scalebroom
  Lepidospartum squamatum var. palmeri (A. Gray) L.C. Wheeler -- not accepted
  Leptochloa fascicularis (Lam.) A. Gray -- not accepted -- bearded sprangletop, sprangletop
  Leptochloa fascicularis var. fascicularis (Lam.) A. Gray -- not accepted -- bearded sprangletop
  Leptodactylon nuttallii (A. Gray) Rydb. -- not accepted
  Leptodactylon pungens ssp. squarrosum (A. Gray) Tidestr. -- not accepted
  Leptodactylon watonii (A. Gray) Rydb. -- not accepted
  Leptodactylon watsonii (A. Gray) Rydb. -- not accepted -- Watson's prickly gilia, Watson's prickly phlox
  Leptoglossis texana (Torr.) A. Gray -- not accepted
  Leptopoda fimbriata Torr. & A. Gray non Leptopoda fimbriata (Michx.) Eaton -- not accepted
  Leptosiphon aureus ssp. decorus (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- golden linanthus
  Leptosiphon bolanderi (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- Bolander's linanthus
  Leptosiphon breviculus (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- Mojave linanthus
  Leptosiphon floribundum (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- many-flower linanthus
  Leptosiphon floribundum ssp. floribundum (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- manyflower linanthus
  Leptosiphon floribundus (A. Gray) J.M. Porter & L.A. Johnson -- not accepted
  Leptosiphon floribundus ssp. floribundus (A. Gray) J.M. Porter & L.A. Johnson -- not accepted
  Leptosiphon lemmonii (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- Lemmon's linanthus
  Leptosiphon nuttallii (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- Nuttall's linanthus
  Leptosiphon nuttallii ssp. nuttallii (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- Nuttall's linanthus
  Leptosiphon rattanii (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- Rattan's linanthus
  Leptosyne bigelovii (A. Gray) A. Gray -- not accepted
  Leptosyne stillmanii A. Gray -- not accepted
  Lespedeza capitata var. vulgaris Torr. & A. Gray -- not accepted
  Lespedeza hirta var. sparsiflora Torr. & A. Gray -- not accepted
  Lesquerella angustifolia (Nutt. ex Torr. & A. Gray) S. Watson -- not accepted -- annual bladderpod, thread-leaved bladderpod, threadleaf bladderpod
  Lesquerella argyraea (A. Gray) S. Watson -- not accepted -- bladderpod, silver bladderpod
  Lesquerella auriculata (Engelm. & A. Gray) S. Watson -- not accepted -- earleaf bladderpod
  Lesquerella densiflora (A. Gray) S. Watson -- not accepted -- denseflower bladderpod
  Lesquerella engelmannii (A. Gray) S. Watson -- not accepted -- Engelmann's bladderpod
  Lesquerella fendleri (A. Gray) S. Watson -- not accepted -- Fendler bladderpod, Fendler's bladderpod
  Lesquerella gordonii (A. Gray) S. Watson -- not accepted -- Gordon's bladderpod
  Lesquerella gordonii var. gordonii (A. Gray) S. Watson -- not accepted -- Gordon's bladderpod
  Lesquerella gracilis ssp. nuttallii (Torr. & A. Gray) Rollins & E.A. Shaw -- not accepted -- Nuttall's bladderpod
  Lesquerella lasiocarpa (Hook. ex A. Gray) S. Watson -- not accepted -- roughpod bladderpod
  Lesquerella lasiocarpa ssp. berlandieri (A. Gray) Rollins & E.A. Shaw -- not accepted
  Lesquerella lasiocarpa ssp. berlandieri var. berlandieri (A. Gray) Payson -- not accepted -- roughpod bladderpod
  Lesquerella lasiocarpa ssp. lasiocarpa (Hook. ex A. Gray) S. Watson -- not accepted -- roughpod bladderpod
  Lesquerella lasiocarpa var. berlandieri (A. Gray) Payson -- not accepted -- roughpod bladderpod
  Lesquerella lasiocarpa var. lasiocarpa (Hook. ex A. Gray) S. Watson -- not accepted -- roughpod bladderpod
  Lesquerella lescurii (A. Gray) S. Watson -- not accepted -- Lescur's bladderpod
  Lesquerella lindheimeri (A. Gray) S. Watson -- not accepted -- Lindheimer's bladderpod
  Lesquerella montana (A. Gray) S. Watson -- not accepted -- mountain bladderpod
  Lesquerella nuttallii (Torr. & A. Gray) S. Watson -- not accepted
  Lesquerella pallida (Torr. & A. Gray) S. Watson -- not accepted -- white bladderpod
  Lesquerella purpurea (A. Gray) S. Watson -- not accepted -- purple bladderpod, rose bladderpod
  Lesquerella purpurea var. purpurea (A. Gray) S. Watson -- not accepted
  Lesquerella recurvata (Engelm. ex A. Gray) S. Watson -- not accepted -- gaslight bladderpod
  Lessingia germanorum var. glandulifera (A. Gray) J.T. Howell -- not accepted
  Lessingia germanorum var. lemmonii (A. Gray) J.T. Howell -- not accepted
  Lessingia germanorum var. tenuis (A. Gray) J.T. Howell -- not accepted
  Lessingia glandulifera A. Gray -- accepted -- valley lessingia
  Lessingia glandulifera var. glandulifera A. Gray -- accepted -- Lemmon's lessingia, valley lessingia
  Lessingia lemmonii A. Gray -- not accepted -- Lemmon's bladderpod, Lemmon's lessingia, Lemmon's vinegar-weed
  Lessingia lemmonii var. lemmonii A. Gray -- not accepted -- Lemmon's lessingia, Lemmon's vinegarweed
  Lessingia leptoclada A. Gray -- accepted -- Sierra lessingia
  Lessingia nana A. Gray -- accepted -- dwarf lessingia
  Lessingia ramulosa A. Gray -- accepted -- Sonoma lessingia
  Lessingia ramulosa var. adenophora (Greene) A. Gray -- not accepted -- Sonoma lessingia
  Lessingia ramulosa var. ramulosa A. Gray -- not accepted -- Sonoma lessingia
  Lessingia tenuis (A. Gray) Coville -- accepted -- spring lessingia
  Lessingia virgata A. Gray -- accepted -- wand lessingia
  Lessingia virgata var. virgata A. Gray -- not accepted -- wand lessingia
  Leucampyx newberryi A. Gray -- not accepted
  Leuciva dealbata (A. Gray) Rydb. -- accepted -- woolly marsh elder
  Leucocrinum Nutt. ex A. Gray -- accepted -- starlily
  Leucocrinum montanum Nutt. ex A. Gray -- accepted -- common starlily, star-lily
  Leucophyllum minus A. Gray -- accepted -- Big Bend barometerbush, big bend cenizo
  Leucophysalis nana (A. Gray) Averett -- accepted -- dwarf chamaesaracha, dwarf leucophysalis
  Leucosyris carnosa (A. Gray) Greene -- not accepted
  Leucosyris carnosa var. intricata (A. Gray) Cronquist -- not accepted
  Leucothoe catesbaei (Walter) A. Gray -- not accepted
  Leucothoe davisiae Torr. ex A. Gray -- accepted -- Sierra laurel
  Leucothoe racemosa (L.) A. Gray -- not accepted -- swamp doghobble
  Leucothoe recurva (Buckley) A. Gray -- not accepted -- redtwig doghobble
  Levenworthia stylosa A. Gray -- not accepted
  Levenworthia torulosa A. Gray -- not accepted
  Lewisia brachycalyx Engelm. ex A. Gray -- accepted -- short-sepal bitter-root, shortsepal bitterroot, shortsepal lewisia
  Lewisia columbiana (Howell ex A. Gray) B.L. Rob. -- accepted -- Columbian lewisia
  Lewisia columbiana var. columbiana (Howell ex A. Gray) B.L. Rob. -- accepted -- Columbian lewisia
  Lewisia nevadensis (A. Gray) B.L. Rob. -- accepted -- Nevada bitter-root, Nevada bitterroot, Nevada lewisia
  Lewisia pygmaea (A. Gray) B.L. Rob. -- accepted -- alpine bitterroot, alpine lewisia, pigmy bitterroot
  Lewisia pygmaea var. nevadensis (A. Gray) Fosberg -- not accepted
  Lewisia pygmaea var. pygmaea (A. Gray) B.L. Rob. -- not accepted
  Lewisia tweedyi (A. Gray) B.L. Rob. -- not accepted
  Liatris acidota Engelm. & A. Gray -- accepted -- sharp blazing star, sharp gayfeather
  Liatris chapmanii Torr. & A. Gray -- accepted -- Chapman's blazing star
  Liatris compacta (Torr. & A. Gray) Rydb. -- accepted -- scaly blazing star
  Liatris garberi A. Gray -- accepted -- Garber's blazing star
  Liatris graminifolia var. dubia (W. Bartram) A. Gray -- not accepted
  Liatris scariosa var. squarrulosa (Michx.) A. Gray -- not accepted
  Liatris squarrosa var. compacta Torr. & A. Gray -- not accepted -- scaly blazing star
  Liatris X boykinii Torr. & A. Gray (pro sp.) -- accepted -- Boykin's gayfeather
  Ligularia amplectens (A. Gray) W.A. Weber -- not accepted
  Ligularia bigelovii (A. Gray) W.A. Weber -- not accepted
  Ligularia bigelovii var. hallii (A. Gray) W.A. Weber -- not accepted
  Ligularia dentata (A. Gray) H. Hara -- accepted -- summer ragwort
  Ligularia soldanella (A. Gray) W.A. Weber -- not accepted
  Ligularia taraxacoides (A. Gray) W.A. Weber -- not accepted
  Ligusticum apiifolium (Nutt. ex Torr. & A. Gray) A. Gray -- accepted -- celeryleaf licorice-root
  Limnorchis thurberi (A. Gray) Rydb. -- not accepted
  Limnosciadium pumilum (Engelm. & A. Gray) Mathias & Constance -- accepted -- prairie dogshade
  Limonium angustatum (A. Gray) Small -- not accepted
  Limonium carolinianum var. angustatum (A. Gray) S.F. Blake -- not accepted
  Limonium nashii var. angustatum (A. Gray) H.E. Ahles -- not accepted
  Linanthastrum floribundum (A. Gray) Wherry -- not accepted
  Linanthastrum nuttallii (A. Gray) Ewan -- not accepted
  Linanthastrum nuttallii ssp. floribundum (A. Gray) Ewan -- not accepted
  Linanthus aureus ssp. decorus (A. Gray) H. Mason -- not accepted -- golden deserttrumpets, golden linanthus
  Linanthus aureus var. decorus (A. Gray) Jeps. -- not accepted
  Linanthus bellus (A. Gray) Greene -- accepted -- desert beauty
  Linanthus bigelovii (A. Gray) Greene -- accepted -- Bigelow's deserttrumpets, Bigelow's linanthus
  Linanthus bigelovii var. jonesii (A. Gray) Jeps. & H. Mason -- not accepted
  Linanthus bolanderi (A. Gray) Greene -- not accepted -- Bolander's linanthus
  Linanthus breviculus (A. Gray) Greene -- not accepted -- Mojave linanthus
  Linanthus campanulatus (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- bellshape gilia
  Linanthus demissus (A. Gray) Greene -- accepted -- desert linanthus, desertsnow
  Linanthus filiformis (Parry ex A. Gray) J.M. Porter & L.A. Johnson -- accepted -- yellow gilia
  Linanthus floribundus (A. Gray) Greene ex Milliken -- not accepted -- manyflower deserttrumpets, manyflower linanthus
  Linanthus floribundus ssp. floribundus (A. Gray) Greene ex Milliken -- not accepted -- many-flower desert-trumpets, manyflower linanthus
  Linanthus jonesi (A. Gray) Greene -- not accepted
  Linanthus jonesii (A. Gray) Greene -- accepted -- Jones' desert-trumpets, Jones' linanthus
  Linanthus lemmonii (A. Gray) Greene -- not accepted -- Lemmon's linanthus
  Linanthus liniflorus var. pharnaceoides (Benth.) A. Gray -- not accepted
  Linanthus nuttallii (A. Gray) Greene ex Milliken -- not accepted -- Nuttall's desert-trumpets, Nuttall's deserttrumpets, Nuttall's linanthus
  Linanthus nuttallii ssp. floribundus (A. Gray) Munz -- not accepted
  Linanthus nuttallii ssp. nuttallii (A. Gray) Greene ex Milliken -- not accepted -- Nuttall's desert-trumpets, Nuttall's linanthus
  Linanthus orcuttii (Parry & A. Gray) Jeps. -- accepted -- Orcutt's linanthus
  Linanthus parryae (A. Gray) Greene -- accepted -- sandblossoms
  Linanthus rattanii (A. Gray) Greene -- not accepted -- Rattan's linanthus
  Linanthus watsonii (A. Gray) J.M. Porter & L.A. Johnson -- accepted -- Watson's prickly phlox
  Lindheimera A. Gray & Engelm. -- accepted -- lindheimera
  Lindheimera texana A. Gray & Engelm. -- accepted -- Texas star, Texas yellowstar
  Linosyris arborescens A. Gray -- not accepted
  Linosyris carnosa A. Gray -- not accepted
  Linosyris texana Torr. & A. Gray -- not accepted
  Linum adenophyllum A. Gray -- not accepted
  Linum breweri A. Gray -- not accepted
  Linum californicum var. confertum A. Gray ex Trel. -- not accepted
  Linum californicum var. congestum (A. Gray) Jeps. -- not accepted
  Linum congestum A. Gray -- not accepted
  Linum digynum A. Gray -- not accepted
  Linum micranthum A. Gray -- not accepted
  Linum rigidum var. berlandieri (Hook.) Torr. & A. Gray -- not accepted
  Linum rupestre (A. Gray) Engelm. ex A. Gray -- accepted -- rock flax
  Linum spergulinum A. Gray -- not accepted
  Lipocarpha occidentalis (A. Gray) G.C. Tucker -- accepted -- western halfchaff sedge
  Lipochaeta calycosa A. Gray -- not accepted
  Lipochaeta connata var. decurrens A. Gray -- not accepted
  Lipochaeta heterophylla A. Gray -- accepted -- lavaflow nehe
  Lipochaeta integrifolia (Nutt.) A. Gray -- not accepted -- Kure Atoll nehe
  Lipochaeta micrantha (Nutt.) A. Gray -- not accepted -- Kauai nehe, nehe
  Lipochaeta micrantha var. micrantha (Nutt.) A. Gray -- not accepted -- Kauai nehe
  Lipochaeta remyi A. Gray -- not accepted -- annual nehe
  Lipochaeta subcordata A. Gray -- not accepted -- grassland nehe
  Lipochaeta succulenta var. decurrens (A. Gray) Sherff -- not accepted
  Lipochaeta tenuifolia A. Gray -- not accepted -- nehe, Waianae Range nehe
  Lippia wrightii A. Gray -- not accepted
  Lithophragma (Nutt.) Torr. & A. Gray -- accepted -- woodland-star
  Lithophragma affine A. Gray -- accepted -- San Francisco woodland-star
  Lithophragma affine ssp. affine A. Gray -- not accepted -- San Francisco woodland-star
  Lithophragma bolanderi A. Gray -- accepted -- Bolander's woodland-star
  Lithophragma cymbalaria Torr. & A. Gray -- accepted -- mission woodland-star
  Lithospermum californicum A. Gray -- accepted -- California stoneseed
  Lithospermum multiflorum Torr. ex A. Gray -- accepted -- manyflowered gromwell, manyflowered stoneseed, purple pucoon
  Llyonothamnus A. Gray -- not accepted
  Llyonothamnus floribundus A. Gray -- not accepted
  Llyonothamnus floribundus var. floribundus A. Gray -- not accepted
  Lobelia amoena var. glandulifera A. Gray -- not accepted -- southern lobelia
  Lobelia appendiculata var. gattingeri (A. Gray) McVaugh -- not accepted -- Gattinger's lobelia
  Lobelia berlandieri ssp. brachypoda (A. Gray) Lammers -- accepted -- Berlandier's lobelia
  Lobelia berlandieri var. brachypoda (A. Gray) McVaugh -- not accepted -- Berlandier's lobelia
  Lobelia boykinii Torr. & A. Gray ex A. DC. -- accepted -- Boykin's lobelia
  Lobelia brachypoda (A. Gray) A. DC. ex Small -- not accepted
  Lobelia canbyi A. Gray -- accepted -- Canby's lobelia
  Lobelia canbyi var. canbyi A. Gray -- not accepted
  Lobelia dunnii ssp. dunnii var. serrata (A. Gray) McVaugh -- not accepted
  Lobelia dunnii var. serrata (A. Gray) McVaugh -- not accepted -- Dunn's lobelia
  Lobelia feayana A. Gray -- accepted -- bay lobelia
  Lobelia gattingeri A. Gray -- accepted -- Gattinger's lobelia
  Lobelia gaudichaudii var. kauaensis A. Gray -- not accepted
  Lobelia glandulifera (A. Gray) Small -- not accepted
  Lobelia hirtella (A. Gray) Greene -- not accepted
  Lobelia kauaensis (A. Gray) A. Heller -- not accepted -- lava lobelia
  Lobelia spicata var. hirtella A. Gray -- not accepted -- pale-spike lobelia, palespike lobelia
  Lobelia spicata var. parviflora A. Gray -- not accepted
  Lobelia X kauaiensis (A. Gray) A. Heller (pro sp.) -- accepted -- lava lobelia
  Loeselia effusa A. Gray -- not accepted
  Loeselia matthewsii A. Gray -- not accepted
  Loeselia tenuifolia A. Gray -- not accepted
  Loeseliastrum depressum (M.E. Jones ex A. Gray) J.M. Porter -- accepted -- depressed ipomopsis
  Loeseliastrum matthewsii (A. Gray) Timbrook -- not accepted -- desert calico
  Logfia arizonica (A. Gray) Holub -- accepted -- Arizona cottonrose
  Logfia depressa (A. Gray) Holub -- accepted -- dwarf cottonrose
  Lomatium bicolor var. leptocarpum (Torr. & A. Gray) Schlessman -- accepted -- Wasatch desert parsley, Wasatch desertparsley, Wasatch lomatium
  Lomatium dasycarpum (Torr. & A. Gray) J.M. Coult. & Rose -- accepted -- woollyfruit desertparsley
  Lomatium dasycarpum ssp. dasycarpum (Torr. & A. Gray) J.M. Coult. & Rose -- accepted -- woollyfruit desertparsley
  Lomatium daucifolium (Torr. & A. Gray) J.M. Coult. & Rose -- not accepted
  Lomatium divaricatum (Pursh) Nutt. ex Torr. & A. Gray -- not accepted
  Lomatium foeniculaceum ssp. daucifolium (Torr. & A. Gray) W.L. Theob. -- accepted -- carrot-leaf desert-parsley, desert biscuitroot
  Lomatium foeniculaceum var. daucifolium (Torr. & A. Gray) Cronquist -- not accepted
  Lomatium leptocarpum (Torr. & A. Gray) J.M. Coult. & Rose -- not accepted
  Lomatium lucidum (Nutt. ex Torr. & A. Gray) Jeps. -- accepted -- shiny biscuitroot
  Lomatium macrocarpum (Nutt. ex Torr. & A. Gray) J.M. Coult. & Rose -- accepted -- bigseed biscuitroot, bigseed lomatium, large-fruit desert-parsley, largefruit biscuitroot, long mamma
  Lomatium macrocarpum var. ellipticum (Torr. & A. Gray) Jeps. -- not accepted
  Lomatium nuttallii (A. Gray) J.F. Macbr. -- accepted -- Nuttall's biscuitroot
  Lomatium tenuifolium Nutt. ex Torr. & A. Gray -- not accepted
  Lomatium utriculatum (Nutt. ex Torr. & A. Gray) J.M. Coult. & Rose -- accepted -- common lomatium
  Lonicera albiflora Torr. & A. Gray -- accepted -- western white honeysuckle, white honeysuckle
  Lonicera albiflora var. dumosa (A. Gray) Rehder -- not accepted
  Lonicera caerulea var. villosa (Michx.) Torr. & A. Gray -- not accepted
  Lonicera dumosa A. Gray -- not accepted
  Lonicera hispidula (Lindl.) Douglas ex Torr. & A. Gray -- accepted -- pink honeysuckle
  Lonicera hispidula var. hispidula (Lindl.) Douglas ex Torr. & A. Gray -- accepted -- pink honeysuckle
  Lonicera hispidula var. vacillans A. Gray -- accepted -- pink honeysuckle
  Lonicera morrowii A. Gray -- accepted -- Morrow's honeysuckle
  Lonicera sullivantii A. Gray -- not accepted
  Lophochlaena refracta A. Gray -- not accepted
  Lorandersonia pulchella (A. Gray) Urbatsch, R.P. Roberts & Neubig -- accepted -- southwestern rabbitbrush
  Lotus argophyllus (A. Gray) Greene -- not accepted -- silver bird's-foot trefoil
  Lotus argophyllus var. argophyllus (A. Gray) Greene -- not accepted -- silver bird's-foot trefoil
  Lotus argophyllus var. fremontii (A. Gray) Ottley -- not accepted -- Fremont's birdsfoot trefoil
  Lotus heermannii var. orbicularis (A. Gray) Isely -- not accepted -- Heermann's bird's-foot trefoil
  Lotus oblongifolius var. nevadensis (A. Gray) Munz -- not accepted
  Lotus oblongifolius var. torreyi (A. Gray) Ottley -- not accepted
  Lotus oroboides var. nanus (A. Gray) Isely -- not accepted
  Lotus torreyi (A. Gray) Greene -- not accepted
  Lotus wrightii (A. Gray) Greene -- not accepted -- Wright deervetch, Wright's deervetch
  Lowellia aurea A. Gray -- not accepted
  Ludwigia cylindrica var. brachycarpa Torr. & A. Gray -- not accepted
  Ludwigia glandulosa ssp. brachycarpa (Torr. & A. Gray) C.I. Peng -- accepted -- cylindricfruit primrose-willow
  Ludwigia linearis var. puberula Engelm. & A. Gray -- not accepted
  Ludwigia spathulata Torr. & A. Gray -- accepted -- spoon primrose-willow
  Luffa cylindrica var. insularum (A. Gray) Cogn. -- not accepted
  Luina nardosmia (A. Gray) Cronquist -- not accepted
  Lupinus argenteus var. argophyllus (A. Gray) S. Watson -- not accepted
  Lupinus argenteus var. meionanthus (A. Gray) Barneby -- accepted -- Lake Tahoe lupine
  Lupinus argophyllus (A. Gray) Cockerell -- not accepted
  Lupinus aridus var. lobbii A. Gray ex S. Watson -- not accepted
  Lupinus aridus var. torreyi (A. Gray ex S. Watson) C.P. Sm. -- not accepted
  Lupinus breweri A. Gray -- accepted -- Brewer's lupine
  Lupinus breweri var. breweri A. Gray -- accepted -- Brewer's lupine
  Lupinus caudatus ssp. argophyllus (A. Gray) L.Ll. Phillips -- accepted -- Kellogg spurred lupine, Kellogg's spurred lupine
  Lupinus caudatus var. argophyllus (A. Gray) S.L. Welsh -- not accepted
  Lupinus danaus A. Gray -- not accepted
  Lupinus decumbens var. argophyllus A. Gray -- not accepted
  Lupinus falcifer Nutt. ex Torr. & A. Gray (pro. syn.) -- not accepted
  Lupinus foliosus (Torr. & A. Gray) Nutt. ex Hook. -- not accepted
  Lupinus laxiflorus var. argophyllus (A. Gray) M.E. Jones -- not accepted
  Lupinus laxiflorus var. foliosus Torr. & A. Gray -- not accepted
  Lupinus laxiflorus var. tenellus (Douglas ex G. Don) Torr. & A. Gray -- not accepted
  Lupinus lepidus var. lobbii (A. Gray ex S. Watson) C.L. Hitchc. -- not accepted
  Lupinus lepidus var. torreyi (A. Gray ex S. Watson) Jeps. -- not accepted
  Lupinus lobbii (A. Gray ex S. Watson) A. Gray ex Greene -- not accepted
  Lupinus lyallii A. Gray -- accepted -- dwarf mountain lupine, Lyall's lupine
  Lupinus lyallii ssp. lyallii A. Gray -- accepted -- dwarf mountain lupine, Lyall's lupine
  Lupinus lyallii ssp. lyallii var. danaus (A. Gray) S. Watson -- not accepted -- dwarf mountain lupine, Lyall's lupine
  Lupinus lyallii ssp. lyallii var. lyallii A. Gray -- not accepted -- dwarf mountain lupine, Lyall's lupine
  Lupinus lyallii var. danaus (A. Gray) S. Watson -- accepted -- dwarf mountain lupine
  Lupinus lyallii var. lobbii (A. Gray ex S. Watson) C.P. Sm. -- not accepted
  Lupinus lyallii var. lyallii A. Gray -- accepted -- dwarf mountain lupine
  Lupinus meionanthus A. Gray -- not accepted -- Lake Tahoe lupine, Tahoe lupine
  Lupinus polyphyllus ssp. polyphyllus var. grandifolius (Lindl. ex J. Agardh) Torr. & A. Gray -- not accepted -- bigleaf lupine
  Lupinus polyphyllus var. grandifolius (Lindl. ex J. Agardh) Torr. & A. Gray -- accepted -- bigleaf lupine
  Lupinus sellulus ssp. sellulus var. lobbii (A. Gray ex S. Watson) B.J. Cox -- not accepted -- Donner Lake lupine, Lobb's lupine
  Lupinus sellulus var. lobbii (A. Gray ex S. Watson) B.J. Cox -- accepted -- Donner Lake lupine
  Lupinus villosus var. diffusus (Nutt.) Torr. & A. Gray -- not accepted
  Lycium andersonii A. Gray -- accepted -- Anderson wolfberry, Anderson's wolfberry, water jacket
  Lycium andersonii var. andersonii A. Gray -- accepted -- Anderson wolfberry, Anderson's wolfberry, water jacket
  Lycium andersonii var. wrightii A. Gray -- accepted -- water jacket, Wright wolfberry
  Lycium berlandieri var. parviflorum (A. Gray) A. Terracc. -- accepted -- Berlandier's wolfberry, small Berlandier wolfberry
  Lycium californicum Nutt. ex A. Gray -- accepted -- California desert-thorn, California wolfberry
  Lycium californicum var. arizonicum A. Gray -- accepted
  Lycium californicum var. californicum Nutt. ex A. Gray -- accepted -- California desert-thorn
  Lycium carolinianum var. sandwicense (A. Gray) C.L. Hitchc. -- not accepted
  Lycium cooperi A. Gray -- accepted -- Cooper wolfberry, Cooper's wolfberry, peach thorn
  Lycium exsertum A. Gray -- accepted -- Arizona desert-thorn, littleleaf wolfberry
  Lycium fremontii A. Gray -- accepted -- Fremont wolfberry, Fremont's desert-thorn
  Lycium macrodon A. Gray -- accepted -- desert wolfberry
  Lycium parishii A. Gray -- accepted -- Parish wolfberry, Parish's desert-thorn, Parish's wolfberry
  Lycium puberulum A. Gray -- accepted -- downy desert-thorn, downy wolfberry
  Lycium puberulum var. puberulum A. Gray -- accepted -- downy desert-thorn, downy desertthorn
  Lycium richii A. Gray -- not accepted -- Baja desert-thorn
  Lycium sandwicense A. Gray -- accepted -- Hawai'i desert-thorn
  Lycium shockleyi A. Gray -- accepted -- Shockley's desert-thorn, Shockley's wolfberry
  Lycium torreyi A. Gray -- accepted -- squawthorn, Torrey wolfberry, Torrey's wolfberry
  Lycopersicon esculentum var. cerasiforme (Dunal) A. Gray -- not accepted
  Lycopus lucidus ssp. americanus (A. Gray) Hultén -- not accepted
  Lycopus lucidus var. americanus A. Gray -- not accepted
  Lycopus sessilifolius A. Gray -- not accepted
  Lygodesma grandiflora (Nutt.) Torr. & A. Gray -- not accepted
  Lygodesmia aphylla var. texana Torr. & A. Gray -- not accepted
  Lygodesmia bigelovii (A. Gray) Shinners -- not accepted
  Lygodesmia exigua (A. Gray) A. Gray -- not accepted
  Lygodesmia grandiflora (Nutt.) Torr. & A. Gray -- accepted -- largeflower skeletonplant, largeflower skeletonweed, rush-pink
  Lygodesmia grandiflora var. grandiflora (Nutt.) Torr. & A. Gray -- accepted
  Lygodesmia rostrata (A. Gray) A. Gray -- not accepted
  Lygodesmia texana (Torr. & A. Gray) Greene -- accepted -- Texas skeletonplant
  Lygodesmia thurberi (A. Gray) Shinners -- not accepted
  Lygodesmia wrightii (A. Gray) Shinners -- not accepted
  Lyonothamnus A. Gray -- accepted -- Catalina ironwood
  Lyonothamnus floribundus A. Gray -- accepted -- Catalina ironwood
  Lyonothamnus floribundus ssp. floribundus A. Gray -- not accepted -- Catalina ironwood
  Lysias hookeriana (Torr. ex A. Gray) Rydb. -- not accepted
  Lysimachia daphnoides (A. Gray) Hillebr. -- accepted -- lehua makanoe
  Lysimachia hillebrandii Hook. f. ex A. Gray -- accepted -- pua-hekili
  Lysimachia hillebrandii var. angustifolia A. Gray -- not accepted
  Lysimachia lanceolata var. angustifolia (Lam.) A. Gray -- not accepted
  Lysimachia lanceolata var. hybrida (Michx.) A. Gray -- not accepted
  Lysimachia X producta (A. Gray) Fernald (pro. sp.) -- accepted -- loosestrife
  Lysimachiopsis angustifolia (A. Gray) O. Deg. & I. Deg. -- not accepted
  Lythrum alatum var. lanceolatum (Elliott) Torr. & A. Gray ex Rothr. -- accepted -- winged lythrum
  Lythrum californicum Torr. & A. Gray -- accepted -- California loosestrife
  Macdougalia bigelovii (A. Gray) A. Heller -- not accepted
  Machaeranthera aurea (A. Gray) Shinners -- not accepted -- Houston tansyaster
  Machaeranthera bigelovii (A. Gray) Greene -- not accepted -- Bigelow's machaeranthera, Bigelow's tansy-aster, Bigelow's tansyaster
  Machaeranthera bigelovii var. bigelovii (A. Gray) Greene -- not accepted -- Bigelow tansyaster, Bigelow's tansyaster
  Machaeranthera blephariphylla (A. Gray) Shinners -- not accepted -- Texas tansyaster
  Machaeranthera canescens (Pursh) A. Gray -- not accepted -- hoary aster, hoary goldenweed, hoary machaeranthera, hoary tansy-aster, hoary tansyaster, purple aster
  Machaeranthera canescens ssp. canescens (Pursh) A. Gray -- not accepted -- hoary tansy-aster, hoary tansyaster, ironplant goldenweed
  Machaeranthera canescens ssp. canescens var. canescens (Pursh) A. Gray -- not accepted -- cutleaf goldenweed, hoary tansy-aster, hoary tansyaster, ironplant goldenweed, spiny goldenweed
  Machaeranthera canescens ssp. canescens var. incana (Lindl.) A. Gray -- not accepted -- cutleaf goldenweed, cutleaf machaeranthera, hoary tansyaster
  Machaeranthera canescens ssp. canescens var. shastensis (A. Gray) B.L. Turner -- not accepted -- Shasta machaeranthera, Shasta tansyaster
  Machaeranthera canescens ssp. glabra (A. Gray) B.L. Turner -- not accepted -- hoary tansyaster
  Machaeranthera canescens ssp. glabra var. glabra A. Gray -- not accepted -- hoary tansyaster
  Machaeranthera canescens var. canescens (Pursh) A. Gray -- not accepted -- hoary tansyaster
  Machaeranthera canescens var. glabra A. Gray -- not accepted -- hoary tansyaster
  Machaeranthera canescens var. latifolia (A. Nelson) S.L. Welsh, non A. Gray -- not accepted
  Machaeranthera canescens var. latifolia A. Gray -- not accepted
  Machaeranthera canescens var. shastensis (A. Gray) B.L. Turner -- not accepted -- Shasta tansyaster
  Machaeranthera canescens var. tephrodes A. Gray -- not accepted
  Machaeranthera canescens var. viridis A. Gray -- not accepted
  Machaeranthera carnosa (A. Gray) G.L. Nesom -- not accepted -- shrubby alkali aster, shrubby alkali tansyaster, shrubby alkaliaster
  Machaeranthera carnosa var. carnosa (A. Gray) G.L. Nesom -- not accepted -- shrubby alkaliaster
  Machaeranthera carnosa var. intricata (A. Gray) G.L. Nesom -- not accepted -- shrubby alkaliaster
  Machaeranthera coloradoensis (A. Gray) Osterh. -- not accepted -- Colorado tansyaster
  Machaeranthera coloradoensis var. coloradoensis (A. Gray) Osterh. -- not accepted -- Colorado tansyaster
  Machaeranthera eradiata (A. Gray) Howell -- not accepted
  Machaeranthera parviflora A. Gray -- not accepted -- small-flower tansy-aster, smallflower tansyaster
  Machaeranthera pattersonii (A. Gray) Greene -- not accepted
  Machaeranthera pruinosa A. Gray -- not accepted
  Machaeranthera pygmaea (A. Gray) Woot. & Standl. -- not accepted
  Machaeranthera shastensis A. Gray -- not accepted
  Machaeranthera shastensis var. eradiata (A. Gray) Cronquist & D.D. Keck -- not accepted
  Machaeranthera sonorae (A. Gray) J. Stucky -- not accepted
  Machaeranthera tephrodes (A. Gray) Greene -- not accepted
  Machaeranthera tortifolia (Torr. & A. Gray) Cronquist & D.D. Keck -- not accepted
  Machaeranthera wrightii (A. Gray) Cronquist & D.D. Keck -- not accepted
  Macromeria viridiflora var. thurberi (A. Gray) I.M. Johnst. -- not accepted -- Thurber's giant-trumpets
  Macronema greenei (A. Gray) Greene -- not accepted
  Macronema watsonii (A. Gray) Greene -- not accepted
  Macroptilium heterophyllum var. rotundifolium (A. Gray) Maréchal, Mascherpa & Stainier -- not accepted
  Macrosiphonia brachysiphon (Torr.) A. Gray -- not accepted -- Huachuca Mountain rocktrumpet
  Madia bolanderi (A. Gray) A. Gray -- not accepted -- Bolander's madia
  Madia dissitiflora (Nutt.) Torr. & A. Gray -- not accepted
  Madia elegans ssp. wheeleri (A. Gray) D.D. Keck -- not accepted -- Wheeler's tarweed
  Madia exigua (Sm.) A. Gray -- accepted -- small tarweed
  Madia minima (A. Gray) D.D. Keck -- not accepted -- least tarweed, oppositeleaved tarweed
  Madia sativa var. congesta Torr. & A. Gray -- not accepted
  Madia yosemitana Parry ex A. Gray -- not accepted -- Yosemite tarweed
  Mahonia nevinii (A. Gray) Fedde -- not accepted -- Nevin's barberry
  Malacothamnus fasciculatus (Nutt. ex Torr. & A. Gray) Greene -- accepted -- Mendocino bushmallow
  Malacothamnus fasciculatus ssp. laxiflorus (A. Gray) Thorne -- not accepted
  Malacothamnus fasciculatus var. laxiflorus (A. Gray) Kearney -- not accepted
  Malacothamnus fremontii (Torr. ex A. Gray) Torr. ex Greene -- accepted -- Fremon's bushmallow
  Malacothamnus paniculatus (A. Gray) Kearney -- not accepted
  Malacothrix californica var. glabrata A. Gray ex D.C. Eaton -- not accepted
  Malacothrix clevelandii A. Gray -- accepted -- Cleveland's desert dandelion, Cleveland's desertdandelion
  Malacothrix coulteri Harv. & A. Gray -- accepted -- snake's head, snake's-head, snakehead desert dandelion
  Malacothrix fendleri A. Gray -- accepted -- Fendler's desert dandelion, Fendler's desertdandelion
  Malacothrix foliosa A. Gray -- accepted -- leafy desertdandelion
  Malacothrix foliosa ssp. foliosa A. Gray -- accepted -- leafy desertdandelion
  Malacothrix glabrata (A. Gray ex D.C. Eaton) A. Gray -- accepted -- smooth desert dandelion, smooth desertdandelion
  Malacothrix incana (Nutt.) Torr. & A. Gray -- accepted -- dunedelion
  Malacothrix platyphylla A. Gray -- not accepted
  Malacothrix saxatilis (Nutt.) Torr. & A. Gray -- accepted -- cliff desert dandelion, cliff desertdandelion
  Malacothrix saxatilis var. commutata (Torr. & A. Gray) Ferris -- accepted -- cliff desertdandelion
  Malacothrix saxatilis var. saxatilis (Nutt.) Torr. & A. Gray -- accepted -- cliff desertdandelion
  Malacothrix saxatilis var. tenuifolia (Nutt.) A. Gray -- accepted -- cliff desert dandelion, cliff desertdandelion
  Malacothrix sonchoides (Nutt.) Torr. & A. Gray -- accepted -- sowthistle desert dandelion, sowthistle desertdandelion, yellow-saucers
  Malacothrix sonchoides var. torreyi (A. Gray) E.W. Williams -- not accepted
  Malacothrix tenuifolia (Nutt.) Torr. & A. Gray -- not accepted
  Malacothrix torreyi A. Gray -- accepted -- Mohave aster, Torrey's desert dandelion, Torrey's desertdandelion
  Malacothrix xanthii A. Gray -- accepted
  Malaxis brachypoda (A. Gray) Fernald -- not accepted -- adder's-mouth, white adder's-mouth orchid
  Malaxis monophyllos ssp. brachypoda (A. Gray) Á. Löve & D. Löve -- not accepted
  Malaxis monophyllos var. brachypoda (A. Gray) F. Morris & E.A. Eames -- accepted
  Malva fasciculata Nutt. ex Torr. & A. Gray -- not accepted
  Malvastrum A. Gray -- accepted -- cheeseweed, false mallow
  Malvastrum angustum A. Gray -- not accepted -- narrow-leaved false mallow
  Malvastrum capense (L.) A. Gray & Harv. -- not accepted
  Malvastrum coccineum (Nutt.) A. Gray -- not accepted
  Malvastrum exile A. Gray -- not accepted
  Malvastrum fasciculatum (Nutt. ex Torr. & A. Gray) Greene -- not accepted
  Malvastrum fasciculatum var. laxiflorum (A. Gray) Munz & I.M. Johnst. -- not accepted
  Malvastrum fremontii Torr. ex A. Gray -- not accepted
  Malvastrum rotundifolium A. Gray -- not accepted
  Malvastrum spicatum (L.) A. Gray -- not accepted
  Malvastrum wrightii A. Gray -- not accepted
  Malvaviscus arboreus var. drummondii (Torr. & A. Gray) Schery -- accepted -- wax mallow
  Malvaviscus drummondii Torr. & A. Gray -- not accepted
  Malvella lepidota (A. Gray) Fryxell -- accepted -- scurfy mallow, scurfymallow
  Malvella sagittifolia (A. Gray) Fryxell -- accepted -- arrowleaf mallow
  Mancoa pubens (A. Gray) Rollins -- not accepted -- Trans-Pecos cress, Transpecos cress
  Marah oregana (Torr. ex A. Gray) Howell -- accepted -- coastal manroot, western wildcucumber
  Marah oreganus (Torr. ex A. Gray) Howell -- not accepted -- coastal manroot, western wildcucumber
  Margaranthus lemmonii A. Gray -- not accepted -- Lemmon's globe berry
  Marina calycosa (A. Gray) Barneby -- accepted -- San Pedro false prairie-clover, San Pedro false prairieclover
  Marina parryi (Torr. & A. Gray) Barneby -- accepted -- Parry dalea, Parry's false prairie-clover, Parry's indigobush
  Matelea arizonica (A. Gray) Shinners -- not accepted -- Arizona milkvine
  Matelea cordifolia (A. Gray) Woodson -- accepted -- Sonoran milkvine
  Matelea cynanchoides (Engelm. & A. Gray) Woodson -- accepted -- prairie milkvine
  Matelea pringlei (A. Gray) Woodson -- accepted -- Pringle's milkvine
  Matelea reticulata (Engelm. ex A. Gray) Woodson -- accepted -- netted milkvine
  Matelea sagittifolia (A. Gray) Woodson ex Shinners -- accepted -- arrowleaf matelea, arrowleaf milkvine
  Matelea shortii (A. Gray) Woodson -- not accepted
  Maurandella (A. Gray) Rothm. -- accepted
  Maurandya wislizeni Engelm. ex A. Gray -- not accepted
  Maurandya wislizenii Engelm. ex A. Gray -- not accepted
  Maximowiczia lindheimeri var. tenuisecta (A. Gray) Cogn. -- not accepted
  Medinilla heterophylla A. Gray -- accepted
  Megapterium brachycarpum (A. Gray) H. Lév. -- not accepted
  Meibomia batocaulis (A. Gray) Kuntze -- not accepted
  Meibomia cinerascens (A. Gray) Kuntze -- not accepted
  Meibomia grahamii (A. Gray) Kuntze -- not accepted
  Meibomia graminea (A. Gray) Kuntze -- not accepted
  Meibomia illinoensis (A. Gray) Kuntze -- not accepted
  Meibomia lineata var. polymorpha (A. Gray) Vail -- not accepted
  Meibomia longifolia (Torr. & A. Gray) Vail -- not accepted
  Meibomia neomexicana (A. Gray) Kuntze -- not accepted
  Meibomia polymorpha (A. Gray) Small -- not accepted
  Meibomia pubens (Torr. & A. Gray) Rydb. -- not accepted
  Meibomia tenuifolia (Torr. & A. Gray) Kuntze -- not accepted
  Meibomia wrightii (Engelm. ex A. Gray) Kuntze -- not accepted
  Melampodium cinereum var. ramosissimum (DC.) A. Gray -- not accepted -- hoary blackfoot
  Melampodium leucanthum Torr. & A. Gray -- accepted -- plains blackfoot, plains blackfoot daisy
  Melampodium longicorne A. Gray -- accepted -- Arizona blackfoot
  Melanobatus leucodermis (Douglas ex Torr. & A. Gray) Greene -- not accepted
  Melanthera remyi (A. Gray) W.L. Wagner & H. Rob. -- accepted -- annual nehe
  Melanthera subcordata (A. Gray) W.L. Wagner & H. Rob. -- accepted
  Melanthera tenuifolia (A. Gray) W.L. Wagner & H. Rob. -- accepted -- Waianae Range nehe
  Melica bromoides Bol. ex A. Gray -- not accepted
  Melica bromoides var. bromoides Bol. ex A. Gray -- not accepted
  Melica mutica var. diffusa (Pursh) A. Gray -- not accepted
  Melica mutica var. glabra (Michx.) A. Gray -- not accepted
  Melica smithii (Porter ex A. Gray) Vasey -- accepted -- mélique de Smith, smith melic grass, Smith oniongrass, Smith's melicgrass
  Melicope barbigera A. Gray -- accepted -- uahiapele
  Melicope cinerea A. Gray -- accepted -- manena
  Melicope clusiifolia (A. Gray) T.G. Hartley & B.C. Stone -- accepted -- kukaemoa
  Melicope elliptica A. Gray -- accepted -- leiohi'iaka
  Melicope rotundifolia (A. Gray) T.G. Hartley & B.C. Stone -- accepted -- roundleaf melicope
  Melicope volcanica (A. Gray) T.G. Hartley & B.C. Stone -- accepted -- volcanic melicope
  Mellichampia A. Gray -- not accepted
  Melochia hirsuta var. glabrescens (C. Presl) A. Gray -- not accepted
  Menodora decemfida (Gillies ex Hook. & Arn.) A. Gray -- accepted -- tenfinger menodora
  Menodora longiflora A. Gray -- accepted -- showy menodora
  Menodora scabra A. Gray -- accepted -- rough menodora
  Menodora scabra var. glabrescens A. Gray -- not accepted
  Menodora scabra var. scabra A. Gray -- not accepted -- rough menodora
  Menodora scoparia Engelm. ex A. Gray -- not accepted
  Menodora spinescens A. Gray -- accepted -- spiny menodora
  Mentzelia albicaulis (Douglas ex Hook.) Douglas ex Torr. & A. Gray -- accepted -- white blazingstar, white-stemmed evening-star, whitestem blazingstar, whitestem stickleaf
  Mentzelia albicaulis var. albicaulis (Hook.) Torr. & A. Gray -- not accepted -- whitestem blazingstar
  Mentzelia congesta Nutt. ex Torr. & A. Gray -- accepted -- united blazingstar, Ventana blazingstar
  Mentzelia congesta var. congesta Nutt. ex Torr. & A. Gray -- not accepted -- Ventana blazingstar
  Mentzelia floridana Nutt. ex Torr. & A. Gray -- accepted -- poorman's patch
  Mentzelia gracilenta Torr. & A. Gray -- accepted -- grass blazingstar
  Mentzelia humilis (A. Gray) J. Darl. -- accepted -- gypsum blazingstar
  Mentzelia humilis var. humilis (A. Gray) J. Darl. -- accepted -- gypsum blazingstar
  Mentzelia laevicaulis (Hook.) Torr. & A. Gray -- accepted -- blazingstar mentzelia, smoothstem blazingstar
  Mentzelia laevicaulis var. laevicaulis (Hook.) Torr. & A. Gray -- accepted -- smoothstem blazingstar
  Mentzelia lindleyi Torr. & A. Gray -- accepted -- Lindley's blazingstar
  Mentzelia micrantha (Hook. & Arn.) Torr. & A. Gray -- accepted -- San Luis blazingstar
  Mentzelia multiflora (Nutt.) A. Gray -- accepted -- Adonis blazingstar, Adonis stickleaf, desert blazingstar, manyflowered mentzelia
  Mentzelia multiflora var. multiflora (Nutt.) A. Gray -- accepted -- Adonis blazingstar, multiflower stickleaf
  Mentzelia nuda (Pursh) Torr. & A. Gray -- accepted -- bractless blazingstar, goodmother, stickleaf mentzelia
  Mentzelia nuda var. nuda (Pursh) Torr. & A. Gray -- accepted -- bractless blazingstar
  Mentzelia pumila Nutt. ex Torr. & A. Gray -- accepted -- dwarf blazingstar, dwarf mentzelia, golden blazingstar
  Mentzelia pumila var. pumila Nutt. ex Torr. & A. Gray -- accepted -- dwarf mentzelia, dwarf stickleaf, golden blazingstar
  Mentzelia torreyi A. Gray -- accepted -- Torrey's blazingstar
  Mentzelia torreyi var. torreyi A. Gray -- accepted -- Torrey's blazingstar
  Mentzelia tricuspis A. Gray -- accepted -- desert blazingstar, spinyhair blazingstar, spinyhair stickleaf
  Menziesia ferruginea ssp. glabella (A. Gray) Calder & Roy L. Taylor -- not accepted
  Menziesia ferruginea var. glabella (A. Gray) M. Peck -- not accepted
  Menziesia glabella A. Gray -- not accepted
  Mertensia lanceolata var. fendleri (A. Gray) A. Gray -- not accepted
  Meryta macrophylla (W. Rich ex A. Gray) Seem. -- accepted
  Mesadenia diversifolia (Torr. & A. Gray) Greene -- not accepted
  Mesadenia floridana (A. Gray) Greene -- not accepted
  Metastelma arizonicum A. Gray -- accepted
  Metastelma blodgettii A. Gray -- accepted
  Metastelma pringlei A. Gray -- accepted
  Metrosideros collina auct. non (J.R. Forst. & G. Forst.) A. Gray -- not accepted
  Metrosideros rugosa A. Gray -- accepted -- lehua papa
  Meximalva filipes (A. Gray) Fryxell -- accepted -- Texas-fan
  Micranthes bryophora (A. Gray) Brouillet & Gornall -- accepted -- bud saxifrage
  Micranthes careyana (A. Gray) Small -- accepted -- Carey's saxifrage, golden eye saxifrage
  Micranthes caroliniana (A. Gray) Small -- accepted -- Carolina saxifrage
  Micranthes tolmiei (Torr. & A. Gray) Brouillet & Gornall -- accepted -- alpine saxifrage, Tolmie's saxifrage
  Micromeria brownei var. pilosiuscula A. Gray -- not accepted -- Browne's savory
  Micromeria pilosiuscula (A. Gray) Small -- not accepted
  Micropus amphibola A. Gray -- not accepted -- Mt. Diablo cottonseed
  Micropus amphibolus A. Gray -- accepted -- Mt. Diablo cottonseed
  Micropus californicus var. subvestitus A. Gray -- accepted -- q-tips
  Microrhamnus ericoides A. Gray -- not accepted
  Microseris alpestris (A. Gray) Q. Jones ex Cronquist -- not accepted
  Microseris bigelovii (A. Gray) Sch. Bip. -- accepted -- coastal silverpuffs
  Microseris douglasii ssp. platycarpha (A. Gray) K.L. Chambers -- accepted -- Douglas' silverpuffs
  Microseris douglasii ssp. tenella (A. Gray) K.L. Chambers -- accepted -- Douglas' silverpuffs
  Microseris douglasii var. platycarpha (A. Gray) B.L. Turner -- not accepted