Integrated Taxonomic Information System - Search Results

Results of: Search in every Kingdom for Taxon Author(s) Name(s) A. Gray OR A Gray 'A. Gray'
 
 Kingdom Plantae
  Abronia cycloptera A. Gray – not accepted
  Abutilon hypoleucum A. Gray – accepted – whiteleaf Indian mallow
  Abutilon palmeri A. Gray – accepted – Palmer's Indian mallow
  Abutilon parvulum A. Gray – accepted – dwarf Indian mallow, dwarf abutilon
  Abutilon sonorae 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 greggii A. Gray – not accepted – catclaw acacia, devilsclaw, Gregg's catclaw, Texas catclaw, catclaw
  Acacia greggii var. greggii A. Gray – not accepted – catclaw acacia, Arizona acacia, catclaw, catclaw mimosa
  Acacia koa A. Gray – accepted – koa
  Acacia richii A. Gray – accepted – Tasmanian wattle
  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 var. gracilens A. Gray – not accepted – slender threeseed mercury
  Acamptopappus shockleyi A. Gray – accepted – Shockley's goldenhead
  Acerates viridiflora var. linearis A. Gray – not accepted
  Achyranthes mutica A. Gray – accepted – blunt chaff flower
  Acleisanthes A. Gray – accepted – trumpets
  Acleisanthes anisophylla A. Gray – accepted – obliqueleaf trumpets
  Acleisanthes berlandieri A. Gray – not accepted
  Acleisanthes crassifolia A. Gray – accepted – Texas trumpets
  Acleisanthes longiflora A. Gray – accepted – angel's trumpets, angel trumpet
  Acnida australis A. Gray – not accepted
  Aconitum reclinatum A. Gray – accepted – trailing white monkshood
  Acronychia heterophylla A. Gray – accepted
  Actinella argentea A. Gray – not accepted
  Actinella richardsonii var. floribunda A. Gray – not accepted
  Actinomeris longifolia A. Gray – not accepted
  Adenophyllum wrightii A. Gray – accepted – Wright's dogweed
  Ageratum littorale A. Gray – not accepted – Cape Sable whiteweed
  Agrostis alba var. aristata A. Gray – not accepted
  Agrostis vulgaris var. aristata A. Gray – not accepted
  Alisma lanceolatum A. Gray – not accepted – lanceleaf water plantain
  Allium occidentale A. Gray – not accepted
  Amauria dissecta A. Gray – not accepted
  Ambrosia canescens A. Gray – accepted – hairy ragweed
  Ambrosia cheiranthifolia A. Gray – accepted – Rio Grande ragweed, South Texas ambrosia
  Amianthium A. Gray – accepted – amianthium
  Amoreuxia malvifolia A. Gray – accepted
  Amoreuxia wrightii A. Gray – accepted – Wright's yellowshow
  Amsinckia echinata A. Gray – not accepted
  Amsinckia tessellata A. Gray – accepted – western fiddleneck, bristly fiddleneck
  Amsinckia tessellata var. tessellata A. Gray – accepted – bristly fiddleneck
  Amsonia brevifolia A. Gray – not accepted
  Amsonia palmeri A. Gray – accepted – Palmer's bluestar
  Anaphalis margaritacea var. subalpina A. Gray – not accepted
  Ancistrocarphus A. Gray – accepted – woolly fishhooks, neststraw
  Ancistrocarphus filagineus A. Gray – accepted – hooded neststraw, false neststraw
  Androsace arizonica A. Gray – not accepted
  Androsace septentrionalis var. subulifera A. Gray – not accepted
  Anemone cylindrica A. Gray – accepted – cottonweed, candle anemone
  Anemone oregana A. Gray – accepted – blue windflower
  Anemone oregana var. oregana A. Gray – accepted – blue windflower
  Angelica breweri A. Gray – accepted – Brewer's angelica
  Angelica lineariloba A. Gray – accepted – Sierra angelica, poison angelica
  Anisacanthus insignis A. Gray – not accepted
  Anoda abutiloides A. Gray – accepted – Indian anoda
  Anoda arizonica A. Gray – not accepted
  Anoda pentaschista A. Gray – accepted – field anoda
  Anoda thurberi A. Gray – accepted – Arizona anoda
  Anoda wrightii A. Gray – not accepted
  Antennaria alpina var. stenophylla A. Gray – not accepted
  Antennaria dimorpha var. flagellaris A. Gray – not accepted
  Antennaria geyeri A. Gray – accepted – pinewoods pussytoes, Geyer's everlasting, mountain pussytoes
  Antennaria microcephala A. Gray – not accepted
  Antirrhinum breweri A. Gray – not accepted
  Antirrhinum cooperi A. Gray – not accepted
  Antirrhinum filipes A. Gray – not accepted
  Antirrhinum leptaleum A. Gray – not accepted
  Antirrhinum maurandioides A. Gray – not accepted
  Antirrhinum subcordatum A. Gray – not accepted – dimorphic snapdragon
  Antirrhinum subsessile A. Gray – not accepted
  Antirrhinum virga A. Gray – not accepted
  Aphanostephus arizonicus A. Gray – not accepted
  Aphantochaeta exilis A. Gray – not accepted
  Aphyllon cooperi A. Gray – not accepted
  Apocynum album var. hypericifolium A. Gray – not accepted
  Apocynum androsaemifolium ssp. pumilum var. pumilum A. Gray – not accepted – low dogbane
  Apocynum androsaemifolium var. pumilum A. Gray – not accepted
  Apodanthera undulata A. Gray – accepted – melon-loco, melon loco
  Apodanthera undulata var. undulata A. Gray – accepted
  Aquilegia chrysantha A. Gray – accepted – golden columbine
  Aquilegia chrysantha var. chrysantha A. Gray – not accepted – golden columbine
  Arabis drummondii A. Gray – not accepted – Canadian rockcress, Drummond rockcress, Drummond's rockcress
  Arabis platysperma A. Gray – not accepted – pioneer rockcress
  Arabis platysperma var. platysperma A. Gray – not accepted – pioneer rockcress
  Arbutus xalapensis var. arizonica A. Gray – not accepted
  Arctostaphylos andersonii A. Gray – accepted – Santa Cruz manzanita
  Arctostaphylos nevadensis A. Gray – accepted – pinemat manzanita
  Arctostaphylos nevadensis ssp. nevadensis A. Gray – accepted – pinemat manzanita, pine-mat manzanita
  Arctostaphylos nummularia A. Gray – accepted – glossyleaf manzanita
  Arctostaphylos nummularia A. Gray – not accepted
  Arctostaphylos nummularia ssp. nummularia A. Gray – accepted – glossyleaf manzanita
  Arenaria fendleri A. Gray – not accepted – Fendler's sandwort
  Arenaria fendleri var. fendleri A. Gray – not accepted – Fendler's sandwort
  Arenaria saxosa A. Gray – not accepted
  Argemone hispida A. Gray – accepted – rough pricklypoppy, rough prickly poppy
  Argyroxiphium macrocephalum A. Gray – not accepted
  Argythamnia adenophora A. Gray – not accepted – glandular silverbush
  Aristida dichotoma var. curtissii A. Gray – accepted – Curtis' threeawn
  Aristida gracilis var. depauperata A. Gray – not accepted
  Aristida ramosissima var. uniaristata A. Gray – not accepted
  Arnica foliosa var. incana A. Gray – not accepted
  Arnica nevadensis A. Gray – accepted – Nevada arnica
  Arnica parryi A. Gray – accepted – Parry's arnica, Sonne's arnica, nodding 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
  Artemisia bigelovii A. Gray – accepted – Bigelow sage, Bigelow sagebrush, Bigelow's sagebrush
  Artemisia bolanderi A. Gray – not accepted
  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 rothrockii A. Gray – accepted – timberline sagebrush
  Artemisia scopulorum A. Gray – accepted – alpine sagebrush, dwarf sagebrush
  Artemisia tridentata var. angustifolia A. Gray – not accepted
  Asclepias curtissii A. Gray – accepted – Curtiss' milkweed
  Asclepias hallii A. Gray – accepted – Hall's milkweed
  Asclepias lemmonii A. Gray – accepted – bigleaf milkweed, Lemmon's milkweed, big-leaf milkweed
  Asclepias nyctaginifolia A. Gray – accepted – Mojave milkweed
  Asclepias quinquedentata A. Gray – accepted – slim-pod milkweed, slimpod milkweed
  Asclepias stenophylla A. Gray – accepted – slimleaf milkweed
  Aspicarpa hyssopifolia A. Gray – accepted – hyssopleaf asphead
  Aspicarpa longipes A. Gray – accepted – spreading asphead
  Aster ascendens var. yosemitanus A. Gray – not accepted
  Aster bigelovii A. Gray – not accepted
  Aster blepharophyllus A. Gray – not accepted
  Aster bloomeri A. Gray – not accepted
  Aster coloradoensis 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 var. sandwicensis A. Gray – not accepted
  Aster engelmannii var. glaucescens A. Gray – not accepted
  Aster engelmannii var. ledophyllus A. Gray – not accepted
  Aster ericoides var. pringlei A. Gray – not accepted
  Aster ericoides var. pusillus A. Gray – not accepted
  Aster exilis var. australis A. Gray – not accepted
  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. eatonii A. Gray – not accepted
  Aster foliaceus var. frondeus A. Gray – not accepted
  Aster fremontii var. parishii 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 laevis var. geyeri A. Gray – not accepted – Geyer's smooth aster
  Aster lemmonii A. Gray – not accepted
  Aster longifolius var. villicaulis A. Gray – not accepted
  Aster novi-belgii var. litoreus A. Gray – not accepted – New Belgium aster
  Aster oblongifolius var. rigidulus A. Gray – not accepted
  Aster occidentalis var. intermedius A. Gray – not accepted – intermediate aster
  Aster parryi A. Gray – not accepted
  Aster pattersonii A. Gray – not accepted
  Aster porteri A. Gray – not accepted – Porter's aster
  Aster potosinus A. Gray – not accepted – Santa Rita Mountain aster
  Aster ptarmicoides var. georgianus A. Gray – not accepted
  Aster puniceus var. lucidulus A. Gray – not accepted
  Aster radulinus A. Gray – not accepted – roughleaf aster
  Aster scopulorum A. Gray – not accepted
  Aster shastensis var. eradiatus A. Gray – not accepted
  Aster sonorae A. Gray – not accepted
  Aster stenomeres A. Gray – not accepted
  Aster umbellatus var. latifolius A. Gray – not accepted
  Aster umbellatus var. pubens A. Gray – not accepted
  Aster watsonii A. Gray – not accepted
  Aster wrightii A. Gray – not accepted
  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 aridus A. Gray – accepted – annual desert milkvetch
  Astragalus arizonicus A. Gray – accepted – Arizona milkvetch, Arizona locoweed
  Astragalus arrectus A. Gray – accepted – Palouse milkvetch
  Astragalus arthu-schottii A. Gray – not accepted
  Astragalus bicristatus A. Gray – accepted – twocrested milkvetch
  Astragalus bigelovii A. Gray – not accepted
  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 casei A. Gray – accepted – Case's 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 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 diphysus A. Gray – not accepted
  Astragalus dispermus A. Gray – not accepted
  Astragalus diversifolius A. Gray – accepted – meadow milkvetch, locoweed
  Astragalus drepanolobus A. Gray – not accepted
  Astragalus flavus var. candicans A. Gray – not accepted
  Astragalus geyeri A. Gray – accepted – Geyer's milkvetch
  Astragalus geyeri var. geyeri A. Gray – accepted – Geyer's milkvetch
  Astragalus glabriusculus var. major A. Gray – not accepted
  Astragalus greenei A. Gray – not accepted
  Astragalus hallii A. Gray – accepted – Hall's milkvetch, Hall milkvetch
  Astragalus hallii var. hallii A. Gray – accepted – Hall's milkvetch, Hall 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 milkvetch, Mancos milk-vetch
  Astragalus humistratus A. Gray – accepted – groundcover milkvetch, ground-cover milkvetch
  Astragalus humistratus var. humistratus A. Gray – accepted – groundcover milkvetch
  Astragalus ineptus A. Gray – not accepted
  Astragalus kentrophyta A. Gray – accepted – spiny milkvetch, spiny milk-vetch
  Astragalus kentrophyta var. kentrophyta A. Gray – accepted – spiny milkvetch, spiny milk-vetch
  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. floribundus A. Gray – accepted – freckled milkvetch, Carson City milkvetch, speckledpod milkvetch
  Astragalus leptaleus A. Gray – accepted – park milkvetch
  Astragalus lyallii A. Gray – accepted – Lyall's milkvetch
  Astragalus malacus A. Gray – accepted – shaggy milkvetch
  Astragalus menziesii A. Gray – not accepted
  Astragalus microcystis A. Gray – accepted – dwarf milkvetch
  Astragalus mokiacensis A. Gray – not accepted – Mokiak 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 oocarpus A. Gray – accepted – Descanso milk-vetch, egg-pod milkvetch
  Astragalus oxyphysus A. Gray – accepted – Mt. Diablo milkvetch
  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's milkvetch, Patterson 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 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 reventus A. Gray – accepted – Blue Mountain milkvetch
  Astragalus reverchonii A. Gray – not accepted
  Astragalus sabulonum A. Gray – accepted – gravel milkvetch
  Astragalus sclerocarpus A. Gray – accepted – woodypod milkvetch
  Astragalus sericoleucus A. Gray – accepted – silky 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 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 tephrodes A. Gray – accepted – ashen milkvetch
  Astragalus tephrodes var. tephrodes A. Gray – accepted – ashen milkvetch
  Astragalus tetrapterus A. Gray – accepted – fourwing milkvetch, four-wing milkvetch
  Astragalus thurberi A. Gray – accepted – Thurber's milkvetch
  Astragalus tricarinatus A. Gray – accepted – triplerib milkvetch, triple-ribbed milkvetch
  Astragalus tridactylicus A. Gray – accepted – foothill milkvetch
  Astragalus triquetrus A. Gray – not accepted
  Astragalus vaccarum A. Gray – accepted – Cow Spring milkvetch
  Astragalus wardii A. Gray – accepted – Ward's milkvetch
  Astragalus whitneyi A. Gray – accepted – balloonpod milkvetch, balloon milkvetch
  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
  Atrichoseris A. Gray – accepted – atrichoseris
  Ayenia microphylla A. Gray – accepted – shrubby ayenia, dense ayenia, little-leaf ayenia
  Azalea japonica A. Gray – not accepted
  Baccharis bigelovii A. Gray – accepted – Bigelow's false willow, Bigelow baccharis, 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 sarothroides A. Gray – accepted – desertbroom, desert broom, broom baccharis
  Baccharis sergiloides A. Gray – accepted – desert baccharis, squaw waterweed baccharis
  Baccharis wrightii A. Gray – accepted – Wright's baccharis
  Baeria macrantha var. pauciaristata A. Gray – not accepted
  Baeria maritima A. Gray – not accepted
  Bahia bigelovii A. Gray – accepted – Bigelow's bahia
  Bahia biternata A. Gray – accepted – slimlobe bahia, slim-lobe false goldfields
  Bahia nudicaulis A. Gray – not accepted
  Bahia pedata A. Gray – accepted – bluntscale bahia, blunt-scale false goldfields
  Bahia wallacei A. Gray – not accepted
  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
  Barringtonia samoensis A. Gray – accepted
  Bartlettia A. Gray – accepted – bartlettia
  Bartlettia scaposa A. Gray – accepted – Bartlett daisy
  Berberis fendleri A. Gray – accepted – Colorado barberry
  Berberis nevinii A. Gray – accepted – Nevin's barberry
  Berlandiera lyrata var. macrophylla A. Gray – not accepted
  Bidens bigelovii A. Gray – accepted – Bigelow's beggarticks, Bigelow beggarticks, stickseed
  Bidens bigelovii var. bigelovii A. Gray – 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 tenuisecta A. Gray – accepted – slimlobe beggarticks, slim-lobe beggarticks
  Bigelovia brachylepis A. Gray – not accepted
  Bigelovia intricata A. Gray – not accepted
  Bigelovia vaseyi A. Gray – not accepted
  Bobea brevipes A. Gray – accepted – `akupa
  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, Wright's boerhavia, largebract spiderling
  Bolandra A. Gray – accepted – false coolwort
  Bolandra californica A. Gray – accepted – Sierra false coolwort
  Boltonia latisquama A. Gray – not accepted
  Boltonia latisquama var. occidentalis A. Gray – not accepted
  Bonamia menziesii A. Gray – accepted – Hawaii lady's nightcap
  Boschniakia strobilacea A. Gray – not accepted – California groundcone
  Bouchea linifolia A. Gray – accepted – groovestem bouchea
  Bouteloua curtipendula var. aristosa A. Gray – not accepted
  Boykinia major A. Gray – accepted – large boykinia
  Brachyelytrum aristatum var. engelmannii A. Gray – not accepted
  Brickellia atractyloides A. Gray – accepted – spearleaf brickellbush, hollyleaf brickellbush
  Brickellia atractyloides var. atractyloides A. Gray – accepted – spearleaf brickellia
  Brickellia baccharidea A. Gray – accepted – resinleaf brickellbush, baccharisleaf brickellbush, baccharis-leaf brickellia
  Brickellia betonicifolia A. Gray – accepted – betonyleaf brickellbush
  Brickellia brachiata A. Gray – not accepted
  Brickellia coulteri A. Gray – accepted – Coulter's brickellbush
  Brickellia coulteri var. coulteri A. Gray – accepted – Coulter's brickellbush
  Brickellia fendleri A. Gray – not accepted – Fendler's brickellbush
  Brickellia floribunda A. Gray – accepted – Chihuahuan brickellbush, desert brickellbush
  Brickellia frutescens A. Gray – accepted – shrubby brickellbush, rigid brickellbush
  Brickellia grandiflora var. petiolaris A. Gray – not accepted
  Brickellia greenei A. Gray – accepted – Greene's brickellbush
  Brickellia incana A. Gray – accepted – woolly brickellbush, white 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 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 simplex A. Gray – accepted – Sonoran brickellbush
  Brickellia squamulosa A. Gray – not accepted – Mule Mountain brickellbush
  Brighamia A. Gray – accepted
  Brighamia insignis A. Gray – accepted – `olulu, cabbage on a stick
  Bromus kalmii A. Gray – accepted – arctic brome, wild chess, brome de Kalm, Kalm's brome
  Bryanthus breweri A. Gray – not accepted
  Bumelia lanuginosa var. rigida A. Gray – not accepted
  Bursera microphylla A. Gray – accepted – elephant tree, littleleaf elephant tree
  Cabomba caroliniana A. Gray – accepted – fanwort, Carolina fanwort
  Cabomba caroliniana var. caroliniana A. Gray – not accepted – Carolina fanwort, fanwort
  Cacalia decomposita A. Gray – not accepted
  Cacalia floridana A. Gray – not accepted
  Cacalia nardosmia A. Gray – not accepted
  Cacaliopsis A. Gray – accepted – cacaliopsis
  Caesalpinia mexicana A. Gray – not accepted – Mexican holdback, Mexican poinciana
  Calamagrostis inexpansa A. Gray – not accepted
  Calamagrostis inexpansa var. inexpansa 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 sylvatica var. breviseta A. Gray – not accepted
  Calamintha ilicifolia A. Gray – not accepted
  Calandrinia tweedyi A. Gray – not accepted
  Calliandra reticulata A. Gray – not accepted
  Calophanes angusta A. Gray – not accepted
  Calophanes decumbens 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
  Calycoseris A. Gray – accepted – tackstem
  Calycoseris parryi A. Gray – accepted – yellow tackstem
  Calycoseris wrightii A. Gray – accepted – white tackstem
  Calyptridium parryi A. Gray – not accepted
  Calyptridium parryi var. parryi A. Gray – not accepted – pussypaws
  Calystegia sepium var. pubescens A. Gray – not accepted
  Campanula parryi A. Gray – accepted – Parry's harebell, Parry's bellflower
  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
  Cardamine cordifolia A. Gray – accepted – heartleaf bittercress, large mountain bittercress
  Cardamine cordifolia var. cordifolia A. Gray – not accepted – heartleaf bittercress
  Carex debilis var. pubera A. Gray – not accepted – white edge sedge
  Carex grayi var. hispidula A. Gray – not accepted
  Carex lupulina var. pedunculata A. Gray – not accepted
  Carlowrightia A. Gray – accepted – wrightwort
  Carlowrightia arizonica A. Gray – accepted – Arizona carlowrightia, Arizona wrightwort
  Carlowrightia pubens A. Gray – not accepted
  Carlowrightia serpyllifolia A. Gray – accepted – Trans-Pecos wrightwort
  Carphochaete A. Gray – accepted – bristlehead
  Carphochaete bigelovii A. Gray – accepted – Bigelow's bristlehead, Bigelow bush
  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
  Castilleja cinerea A. Gray – accepted – ash-gray 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 – Sierran woolly Indian paintbrush, woolly paintbrush, Sierra woolly Indian paintbrush
  Castilleja lanata ssp. lanata A. Gray – accepted – Sierra woolly Indian paintbrush
  Castilleja laxa A. Gray – not accepted
  Castilleja lemmonii A. Gray – accepted – Lemmon's paintbrush, Lemmon's Indian paintbrush
  Castilleja linoides A. Gray – not accepted
  Castilleja oblongifolia A. Gray – not accepted
  Castilleja plagiotoma A. Gray – accepted – Mojave 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
  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
  Cedronella micrantha A. Gray – not accepted
  Centrostegia leptoceras A. Gray – not accepted
  Centrostegia leptoceris A. Gray – not accepted
  Ceratophyllum echinatum A. Gray – accepted – spineless hornwort
  Cercidium texanum A. Gray – not accepted
  Cercocarpus breviflorus A. Gray – accepted – hairy mountain-mahogany
  Chaenactis carphoclinia A. Gray – accepted – pebble pincushion
  Chaenactis carphoclinia var. carphoclinia A. Gray – accepted – pebble pincushion, Peeble pincushion
  Chaenactis cusickii A. Gray – accepted – Cusick's pincushion
  Chaenactis douglasii var. alpina A. Gray – accepted – alpine dustymaiden, alpine pincushion
  Chaenactis fremontii A. Gray – accepted – pincushion flower, morningbride, Fremont's pincushion
  Chaenactis glabriuscula var. megacephala A. Gray – accepted – yellow pincushion
  Chaenactis nevii A. Gray – accepted – John Day's pincushion
  Chaenactis parishii A. Gray – accepted – Parish's chaenactis
  Chaenactis suffrutescens A. Gray – accepted – Shasta chaenactis
  Chaenactis tanacetifolia A. Gray – not accepted
  Chaenactis xantiana A. Gray – accepted – fleshcolor pincushion, flesh-color pincushion, Xantus pincushion
  Chaetopappa asteroides var. imberbis A. Gray – not accepted
  Chaetopappa parryi A. Gray – accepted – Parry's leastdaisy
  Chorizanthe perfoliata A. Gray – not accepted
  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 var. nana A. Gray – not accepted
  Chrysopsis hispida var. stenophylla A. Gray – not accepted
  Chrysopsis oregona var. scaberrima A. Gray – not accepted
  Chrysopsis villosa var. viscida A. Gray – not accepted
  Chrysopsis wrightii A. Gray – not accepted
  Cimicifuga racemosa var. dissecta A. Gray – not accepted
  Cirsium acaule var. americanum A. Gray – not accepted
  Cirsium californicum A. Gray – not accepted
  Cirsium californicum var. californicum A. Gray – not accepted – California thistle
  Cirsium eriocephalum A. Gray – not accepted
  Cirsium grahamii A. Gray – accepted – Graham's thistle
  Cirsium neomexicanum A. Gray – accepted – New Mexico thistle, powderpuff thistle, Utah thistle, lavender thistle
  Cirsium neomexicanum var. neomexicanum A. Gray – not accepted – New Mexico thistle
  Cirsium ochrocentrum A. Gray – accepted – yellowspine thistle
  Cirsium ochrocentrum ssp. ochrocentrum A. Gray – accepted – yellowspine thistle
  Cirsium wrightii A. Gray – accepted – Wright's thistle, Wright's marsh thistle
  Clappia A. Gray – accepted – clapdaisy
  Clappia A. Gray – not accepted
  Clappia suaedifolia A. Gray – accepted – fleshy clapdaisy
  Clarkia xantiana A. Gray – accepted – gunsight clarkia
  Clarkia xantiana ssp. xantiana A. Gray – accepted – gunsight clarkia
  Claytonia parviflora var. depressa A. Gray – not accepted
  Claytonia sibirica var. bulbifera A. Gray – not accepted – Siberian springbeauty
  Clematis tenuiloba A. Gray – not accepted
  Cleome sandwicensis A. Gray – not accepted
  Cleome sonorae A. Gray – not accepted
  Cleomella oocarpa A. Gray – not accepted
  Cleomella parviflora A. Gray – accepted – small-flower stinkweed, smallflower cleomella, slender cleomella
  Cnicus arizonicus A. Gray – not accepted
  Cnicus breweri var. vaseyi A. Gray – not accepted
  Cnicus parryi A. Gray – not accepted
  Cnicus undulatus var. megacephalus A. Gray – not accepted
  Cnicus wheeleri A. Gray – not accepted
  Coldenia palmeri A. Gray – not accepted
  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 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
  Collomia tenella A. Gray – accepted – diffuse collomia
  Cologania lemmonii A. Gray – not accepted – Lemmon's cologania
  Cologania longifolia A. Gray – not accepted
  Condalia spathulata A. Gray – accepted – squawbush, knifeleaf condalia, knifeleaf snakewood
  Conoclinium dissectum A. Gray – accepted – palmleaf thoroughwort
  Conradina A. Gray – accepted – false rosemary
  Convolvulus hermannioides A. Gray – not accepted
  Convolvulus luteolus var. fulcratus A. Gray – not accepted
  Convolvulus occidentalis A. Gray – not accepted
  Conyza coulteri A. Gray – not accepted
  Conyza coulteri var. tenuisecta A. Gray – not accepted
  Coprosma ernodeoides A. Gray – accepted – `aiakanene
  Coprosma foliosa A. Gray – accepted – forest mirrorplant
  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
  Corchorus hirtus var. glabellus A. Gray – not accepted – Orinoco jute
  Cordylanthus canescens A. Gray – not accepted
  Cordylanthus laxiflorus A. Gray – accepted – nodding bird's-beak, nodding bird's beak
  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. pilosus A. Gray – accepted – hairy bird's beak
  Cordylanthus pringlei A. Gray – accepted – Pringle's bird's beak
  Cordylanthus tenuis A. Gray – accepted – slender bird'sbeak, slender bird's beak
  Cordylanthus tenuis ssp. tenuis A. Gray – accepted – slender bird'sbeak, slender bird's beak
  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
  Coreopsis drummondii var. wrightii A. Gray – not accepted
  Coreopsis leavenworthii var. garberi A. Gray – not accepted
  Coreopsis newberryi A. Gray – not accepted
  Corethrogyne filaginifolia var. rigida A. Gray – not accepted
  Corydalis caseana A. Gray – accepted – Sierra fumewort
  Corydalis caseana ssp. caseana A. Gray – accepted – Sierra fumewort
  Coursetia glandulosa A. Gray – accepted – rosary babybonnets
  Coursetia microphylla 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
  Crepis intermedia A. Gray – accepted – limestone hawksbeard, gray hawksbeard
  Crepis occidentalis var. costata A. Gray – not accepted
  Crepis pleurocarpa A. Gray – accepted – nakedstem hawksbeard
  Croton eutrigynus A. Gray – not accepted
  Crusea wrightii A. Gray – not accepted
  Cucurbita digitata A. Gray – accepted – fingerleaf gourd, coyote gourd
  Cuphea wrightii A. Gray – accepted – Wright's waxweed
  Cyanea leptostegia A. Gray – accepted – giant kokee cyanea, giant koke'e cyanea
  Cyanea pilosa A. Gray – accepted – hairy cyanea
  Cyanea pilosa ssp. pilosa A. Gray – accepted – hairy cyanea
  Cyanea tritomantha A. Gray – accepted – `aku `aku, `aku
  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
  Cynoglossum occidentale A. Gray – accepted – western hound's tongue
  Cypripedium californicum A. Gray – accepted – California lady's slipper
  Cyrtandra dolichocarpa A. Gray – accepted
  Cyrtandra induta A. Gray – accepted
  Cyrtandra labiosa A. Gray – accepted
  Cyrtandra macraei A. Gray – accepted – upland cyrtandra
  Cyrtandra pickeringii A. Gray – accepted – Pickering's cyrtandra
  Cyrtandra platyphylla A. Gray – accepted – `ilihia
  Cyrtandra pogonantha A. Gray – accepted
  Cyrtandra richii A. Gray – accepted
  Cyrtandra samoensis A. Gray – accepted
  Cyrtandra triflora var. gaudichaudii A. Gray – not accepted
  Cyrtandra triflora var. lysiosepala A. Gray – not accepted
  Dalea albiflora A. Gray – accepted – whiteflower prairie clover, white flower dalea, whiteflower prairieclover
  Dalea argyrea A. Gray – not accepted
  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 prairieclover, Fort Bowie prairie-clover
  Dalea calycosa A. Gray – not accepted
  Dalea emoryi A. Gray – not accepted
  Dalea filiformis A. Gray – accepted – Sonoran prairie clover, Sonoran prairie-clover, Sonoran prairieclover
  Dalea frutescens A. Gray – accepted – black prairie clover, black dalea, black prairieclover
  Dalea greggii A. Gray – accepted – Gregg's prairie clover, Gregg's dalea, Gregg's prairieclover
  Dalea hallii A. Gray – accepted – Hall's prairie clover, Hall's prairieclover
  Dalea lachnostachys A. Gray – accepted – glandleaf prairie clover, gland-leaf prairie-clover, glandleaf prairieclover
  Dalea lasiathera A. Gray – accepted – purple dalea, purple prairie clover
  Dalea ordiae A. Gray – not accepted
  Dalea pogonathera A. Gray – accepted – bearded prairie clover, bearded dalea, bearded prairieclover
  Dalea pogonathera var. pogonathera A. Gray – accepted – bearded prairie clover, bearded dalea, bearded prairieclover
  Dalea polygonoides A. Gray – accepted – sixweeks prairie clover, six-weeks prairie-clover, sixweeks prairieclover
  Dalea pringlei A. Gray – accepted – Pringle's prairie clover, Pringle's dalea
  Dalea scoparia A. Gray – not accepted
  Dalea spinosa A. Gray – not accepted
  Dalea thyrsiflora A. Gray – not accepted
  Dalea wislizeni var. sessilis A. Gray – not accepted
  Dalea wrightii A. Gray – accepted – Wright's prairie clover, Wright's prairie-clover, Wright's dalea, Wright's prairieclover
  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 hesperium A. Gray – accepted – foothill larkspur
  Delphinium hesperium ssp. hesperium A. Gray – accepted – foothill 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 var. stachydeum A. Gray – not accepted
  Delphinium trolliifolium A. Gray – accepted – Columbian larkspur
  Desmodium annuum A. Gray – not accepted
  Desmodium batocaulon A. Gray – accepted – San Pedro ticktrefoil, San Pedro tick trefoil
  Desmodium cinerascens A. Gray – accepted – spiked ticktrefoil, spiked tick trefoil
  Desmodium grahamii A. Gray – accepted – Graham's ticktrefoil, Graham's tick trefoil
  Desmodium gramineum A. Gray – accepted – grassleaf ticktrefoil, grass-leaf tick trefoil
  Desmodium illinoense A. Gray – accepted – Illinois ticktrefoil, Illinois tickclover
  Desmodium lineatum var. polymorphum A. Gray – not accepted
  Desmodium neomexicanum A. Gray – accepted – New Mexico ticktrefoil, New Mexico tickclover
  Desmodium psilocarpum A. Gray – accepted – Santa Cruz Island ticktrefoil, Santa Cruz Island tick trefoil
  Desmodium wrightii A. Gray – not accepted
  Dichaetophora A. Gray – accepted – dichaetophora
  Dichaetophora campestris A. Gray – accepted – plainsdaisy
  Dicliptera brachiata var. attenuata A. Gray – not accepted
  Dicliptera pseudoverticillaris A. Gray – not accepted
  Dicliptera torreyi A. Gray – not accepted
  Dicoria brandegeei A. Gray – not accepted
  Dicoria canescens A. Gray – accepted – desert twinbugs
  Dicoria canescens ssp. canescens A. Gray – not accepted – desert twinbugs
  Dicranocarpus A. Gray – accepted – dicranocarpus
  Dicranocarpus parviflorus A. Gray – accepted – pitchfork
  Dimeresia A. Gray – accepted – dimeresia
  Dimeresia howellii A. Gray – accepted – doublet
  Dimersia A. Gray – not accepted
  Dimersia howelli A. Gray – not accepted
  Diodia teres var. angustata A. Gray – not accepted – poorjoe, poor joe
  Diplostelma bellioides A. Gray – not accepted
  Dirca occidentalis A. Gray – accepted – western leatherwood
  Dodecatheon hendersonii A. Gray – not accepted – mosquito bills
  Dodecatheon hendersonii ssp. hendersonii A. Gray – not accepted – mosquito bills
  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
  Downingia bicornuta A. Gray – accepted – double-horned downingia, doublehorn calicoflower
  Downingia bicornuta var. bicornuta A. Gray – accepted – doublehorn calicoflower
  Draba douglasii A. Gray – not accepted
  Draba douglasii var. douglasii A. Gray – not accepted
  Draba eurycarpa A. Gray – not accepted
  Draba streptocarpa A. Gray – accepted – pretty whitlowgrass, pretty draba
  Draba ventosa A. Gray – accepted – wind draba, Wind River draba
  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
  Dubautia laevigata A. Gray – accepted – smooth dubautia
  Dubautia paleata A. Gray – accepted – na`ena`e pua kea
  Dupontia cooleyi A. Gray – not accepted
  Dyssodia cooperi A. Gray – not accepted
  Dyssodia porophylloides A. Gray – not accepted
  Eatonella A. Gray – accepted – eatonella
  Eatonella congdonii A. Gray – not accepted
  Echeveria strictiflora A. Gray – accepted – desert savior
  Echidiocarya californica A. Gray – not accepted
  Elaterium coulteri A. Gray – not accepted
  Elaterium wrightii A. Gray – not accepted
  Elatine brachysperma A. Gray – accepted – shortseed waterwort, short-seed waterwort
  Elatine californica A. Gray – accepted – California waterwort
  Eleocharis bolanderi A. Gray – accepted – Bolander's spikerush
  Elephantopus nudatus A. Gray – accepted – smooth elephantsfoot, naked elephantfoot
  Encelia microcephala A. Gray – not accepted
  Encelia nudicaulis A. Gray – not accepted
  Epilobium obcordatum A. Gray – accepted – rose willowweed, rockfringe
  Eragrostis brevipedicellata A. Gray – not accepted
  Eragrostis tenuis A. Gray – not accepted
  Erigeron acris var. debilis A. Gray – not accepted
  Erigeron andersonii A. Gray – not accepted
  Erigeron argentatus A. Gray – accepted – silver fleabane, silvery daisy
  Erigeron arizonicus A. Gray – accepted – Arizona fleabane
  Erigeron bigelovii A. Gray – accepted – Bigelow's fleabane
  Erigeron biglovii A. Gray – not accepted
  Erigeron bloomeri A. Gray – accepted – scabland fleabane, Bloomer's daisy
  Erigeron bloomeri var. bloomeri A. Gray – accepted – scabland fleabane, scabland daisy
  Erigeron brandegeei A. Gray – not accepted
  Erigeron breweri A. Gray – accepted – Brewer's fleabane, Brewer's daisy
  Erigeron breweri var. breweri A. Gray – accepted – Brewer's fleabane, Brewer's daisy
  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 var. aphanactis A. Gray – not accepted
  Erigeron divergens var. cinereus A. Gray – not accepted
  Erigeron eatonii A. Gray – accepted – Eaton's fleabane, Eaton's daisy
  Erigeron eatonii var. eatonii A. Gray – accepted – Eaton's fleabane, Eaton's daisy
  Erigeron eriophyllis A. Gray – not accepted
  Erigeron eriophyllus A. Gray – not accepted
  Erigeron flagellaris A. Gray – accepted – trailing fleabane, trailing daisy
  Erigeron glabellus var. mollis A. Gray – not accepted
  Erigeron grandiflorus var. elatior A. Gray – not accepted
  Erigeron howellii A. Gray – accepted – Howell's fleabane
  Erigeron inornatus var. angustatus A. Gray – not accepted
  Erigeron inornatus var. viscidulus A. Gray – not accepted
  Erigeron leiomerus A. Gray – accepted – rockslide yellow fleabane, glaber daisy
  Erigeron lemmonii A. Gray – accepted – Lemmon's fleabane, Lemmon 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 fleabane, Parish's daisy
  Erigeron peucephyllus A. Gray – not accepted
  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 repens A. Gray – not accepted
  Erigeron rusbyi A. Gray – not accepted
  Erigeron supplex A. Gray – accepted – supple 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. utahensis A. Gray – accepted – Utah fleabane
  Eriogonum chrysocephalum A. Gray – not accepted
  Eriogonum kelloggii A. Gray – accepted – Red Mountain buckwheat
  Eriogonum parryi A. Gray – 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 torreyanum A. Gray – not accepted
  Eriogonum villiflorum A. Gray – accepted – dairyflower buckwheat, gray buckwheat
  Eriophyllum confertiflorum var. laxiflorum A. Gray – not accepted
  Eriophyllum nevinii A. Gray – not accepted – Nevin's woolly sunflower
  Eriophyllum pringlei A. Gray – accepted – Pringle's woolly sunflower, wooly sunflower, Pringle's eriophyllum
  Eritrichium holopterum A. Gray – not accepted
  Eritrichium oxygonum A. Gray – not accepted
  Erodium texanum A. Gray – accepted – bull filaree, Texas filaree, Texas fillarie, tufted filaree, Texas stork's bill
  Eryngium ravenelii A. Gray – not accepted
  Eryngium wrightii A. Gray – not accepted
  Erythraea calycosa var. arizonica A. Gray – not accepted
  Erythronium propullans A. Gray – accepted – Minnesota fawnlily, Minnesota trout lily, Minnesota dwarf trout lily
  Eugenia sandwicensis A. Gray – not accepted
  Eunanus bicolor A. Gray – not accepted
  Eunanus bigelovii A. Gray – not accepted
  Eunanus coulteri var. angustatus A. Gray – 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 greggii A. Gray – not accepted – palmleaf thoroughwort
  Eupatorium hyssopifolium var. laciniatum A. Gray – accepted – hyssopleaf thoroughwort
  Eupatorium parryi A. Gray – not accepted
  Eupatorium pauperculum A. Gray – not accepted
  Eupatorium rothrockii A. Gray – not accepted
  Eupatorium solidaginifolium A. Gray – not accepted – shrubby thoroughwort
  Eupatorium sonorae A. Gray – not accepted – Sonoran thoroughwort
  Eupatorium wrightii A. Gray – not accepted
  Euphorbia darlingtonii A. Gray – not accepted
  Euphorbia geyeri var. microsperma A. Gray – not accepted
  Euphorbia guilielmii A. Gray – not accepted
  Euphorbia multiformis var. celastroides A. Gray – not accepted
  Eurya sandwicensis A. Gray – accepted – anini
  Evax caulescens var. petiolata A. Gray – not accepted
  Evolvulus arizonicus A. Gray – accepted – hairy evolvulus, wild dwarf morningglory, wild dwarf morning-glory
  Evolvulus laetus A. Gray – not accepted
  Fendlera rupicola var. rupicola A. Gray – accepted – cliff fendlerbush
  Fendlera rupicola var. wrightii A. Gray – accepted – Wright's fendlerbush
  Festuca microstachys var. ciliata A. Gray – not accepted
  Filago arizonica A. Gray – not accepted – Arizona cottonrose
  Filago depressa A. Gray – not accepted – dwarf cottonrose, dwarf filago
  Flaveria chlorifolia A. Gray – accepted – clasping yellowtops
  Forestiera acuminata var. parviflora A. Gray – not accepted
  Forestiera neomexicana A. Gray – not accepted
  Forestiera neomexicana var. arizonica A. Gray – not accepted
  Fragaria virginiana var. illinoensis A. Gray – not accepted
  Frankenia grandifolia var. campestris A. Gray – not accepted
  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 A. Gray – 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
  Fugosia drummondii 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 spathulata A. Gray – accepted – western blanketflower
  Gaillardia spatulata A. Gray – not accepted
  Galactia heterophylla A. Gray – accepted – Gray's milkpea
  Galactia wrightii A. Gray – accepted – Wright's milkpea, Wright milkpea
  Galactia wrightii var. wrightii A. Gray – accepted – Wright's milkpea, Wright milkpea
  Galinsoga parviflora var. semicalva A. Gray – accepted
  Galium andrewsii A. Gray – accepted – phloxleaf bedstraw
  Galium andrewsii ssp. andrewsii A. Gray – accepted – Andrews' bedstraw
  Galium arkansanum A. Gray – accepted – Arkansas bedstraw
  Galium asperrimum A. Gray – not accepted
  Galium asperrimum var. asperulum A. Gray – 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 catalinense A. Gray – accepted – Santa Catalina Island bedstraw
  Galium catalinense ssp. catalinense A. Gray – accepted – Santa Catalina Island 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 – Matthew bedstraw, bushy bedstraw
  Galium microphyllum A. Gray – accepted – bracted bedstraw
  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 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 texense A. Gray – accepted – Texas bedstraw
  Galium trifidum var. pusillum A. Gray – not accepted
  Galium virgatum var. diffusum A. Gray – not accepted
  Galium wrightii A. Gray – accepted – slenderbranch bedstraw, Wright's bedstraw
  Garberia A. Gray – accepted – garberia
  Garrya buxifolia A. Gray – accepted – dwarf silktassel
  Gaultheria ovatifolia A. Gray – accepted – western teaberry
  Gaylussacia frondosa var. nana A. Gray – not accepted – blue huckleberry
  Gaylussacia frondosa var. tomentosa A. Gray – not accepted
  Gayophytum strictum A. Gray – 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 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 quinquefolia var. occidentalis A. Gray – not accepted
  Gentiana setigera A. Gray – accepted – Mendocino gentian
  Gentiana simplex A. Gray – not accepted
  Gentiana wrightii A. Gray – not accepted
  Geranium arboreum A. Gray – accepted – Hawaiian red-flowered geranium, Hawai'i red cranesbill
  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 multiflorum A. Gray – accepted – nohoanu, manyflower geranium
  Geranium ovatifolium A. Gray – not accepted
  Gerardia plukenetii var. microphylla A. Gray – not accepted
  Gerardia purpurea var. paupercula A. Gray – not accepted
  Gilia aggregata var. attenuata A. Gray – not accepted
  Gilia aggregata var. bridgesii A. Gray – not accepted
  Gilia bigelovii A. Gray – not accepted
  Gilia brandegeei A. Gray – not accepted
  Gilia caespitosa A. Gray – not accepted – Rabbit Valley gilia
  Gilia campanulata A. Gray – not accepted – bellflower gilia, bellshape gilia
  Gilia havardii A. Gray – not accepted
  Gilia haydenii A. Gray – not accepted – San Juan gilia
  Gilia leptomeria A. Gray – not accepted – sand gily-flower, slender gilia, sand gilia
  Gilia micromeria A. Gray – not accepted – dainty gilia
  Gilia nevinii A. Gray – accepted – Nevin's gilia
  Gilia nuttallii A. Gray – not accepted
  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 tenerrima A. Gray – not accepted – delicate gilia
  Gilia wrightii A. Gray – not accepted
  Githopsis diffusa A. Gray – accepted – San Gabriel bluecup
  Githopsis diffusa ssp. diffusa A. Gray – accepted – San Gabriel bluecup
  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
  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 wrightii A. Gray – not accepted
  Gonolobus sagittifolius A. Gray – not accepted
  Gouania vitifolia A. Gray – accepted – Oahu chewstick
  Gouldia A. Gray – not accepted
  Gouldia A. Gray – not accepted
  Graphephorum melicoides var. majus A. Gray – not accepted
  Grayia brandegeei A. Gray – accepted – siltbush, spineless hopsage, Brandegee's siltbush
  Greenella A. Gray – accepted
  Greenella arizonica A. Gray – not accepted
  Greenella discoidea A. Gray – not accepted
  Greggia camporum A. Gray – not accepted
  Grindelia arizonica A. Gray – accepted – Arizona gumweed, New Mexican gumweed, cutleaf gumweed
  Grindelia arizonica var. arizonica A. Gray – not accepted – Arizona gumweed
  Grindelia robusta var. angustifolia A. Gray – not accepted
  Guaiacum coulteri A. Gray – accepted
  Guardiola platyphylla A. Gray – accepted – Apache plant
  Gundlachia A. Gray – not accepted
  Gundlachia A. Gray – accepted – gundlachia
  Gutierrezia eriocarpa A. Gray – not accepted
  Gutierrezia gymnospermoides A. Gray – not accepted
  Gutierrezia sphaerocephala A. Gray – accepted – roundleaf snakeweed, round-leaf snakeweed
  Gutierrezia wrightii A. Gray – accepted – Wright's snakeweed
  Habenaria peramoena A. Gray – not accepted
  Halenia rothrockii A. Gray – accepted – southwest spurred gentian, Mt. Graham spurred gentian
  Haploesthes A. Gray – accepted – false broomweed
  Haploesthes greggii A. Gray – accepted – false broomweed
  Haploesthes greggii var. greggii A. Gray – accepted
  Haplopappus apargioides A. Gray – not accepted
  Haplopappus aureus A. Gray – not accepted
  Haplopappus blephariphyllus A. Gray – not accepted
  Haplopappus bloomeri A. Gray – not accepted
  Haplopappus bloomeri var. angustatus A. Gray – not accepted
  Haplopappus brandegeei A. Gray – not accepted
  Haplopappus carthamoides var. cusickii A. Gray – not accepted
  Haplopappus carthamoides var. maximus A. Gray – not accepted
  Haplopappus croceus A. Gray – not accepted
  Haplopappus cuneatus 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 hirtus A. Gray – not accepted
  Haplopappus lanuginosus A. Gray – not accepted
  Haplopappus laricifolius A. Gray – not accepted
  Haplopappus lyallii 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 spinulosus var. canescens A. Gray – not accepted
  Haplopappus spinulosus var. glaber A. Gray – not accepted
  Haplopappus stenophyllus A. Gray – not accepted
  Haplopappus watsonii A. Gray – not accepted
  Haplopappus whitneyi A. Gray – not accepted
  Haplopappus whitneyi var. whitneyi A. Gray – not accepted
  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
  Hecastocleis A. Gray – accepted – hecastocleis
  Hecastocleis shockleyi A. Gray – accepted – prickleleaf
  Hedeoma drummondii var. reverchonii A. Gray – not accepted
  Hedeoma hyssopifolia A. Gray – accepted – mock pennyroyal, falsepennyroyal, aromatic false pennyroyal
  Hedeoma hyssopifolium A. Gray – not accepted
  Hedeoma piperita var. oblongifolia A. Gray – not accepted
  Hedeoma thymoides A. Gray – not accepted
  Hedyotis acerosa A. Gray – not accepted
  Hedyotis humifusa A. Gray – not accepted
  Hedyotis stenophylla var. parviflora A. Gray – not accepted
  Helenium amphilobum A. Gray – not accepted
  Helenium bigelovii A. Gray – accepted – Bigelow's sneezeweed
  Helenium bolanderi A. Gray – accepted – coastal sneezeweed
  Helenium curtisii A. Gray – not accepted
  Helenium hoopesii A. Gray – not accepted
  Helenium lanciniatum A. Gray – accepted
  Helenium nuttallii A. Gray – not accepted
  Helenium ooclinium A. Gray – not accepted
  Helenium thurberi A. Gray – accepted – Thurber's sneezeweed
  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 parryi A. Gray – accepted – Parry's dwarf-sunflower, Parry's dwarfsunflower
  Helianthella pringlei A. Gray – not accepted
  Helianthus bolanderi A. Gray – accepted – serpentine sunflower
  Helianthus cusickii A. Gray – accepted – Cusick's sunflower
  Helianthus exilis A. Gray – accepted – serpentine sunflower
  Helianthus gracilentus A. Gray – accepted – slender sunflower
  Helianthus grosseserratus var. hypoleucus A. Gray – not accepted
  Helianthus laciniatus A. Gray – accepted – alkali sunflower
  Helianthus parishii A. Gray – not accepted
  Helianthus petiolaris var. canescens A. Gray – not accepted
  Helianthus tephrodes A. Gray – not accepted
  Helianthus tuberosus var. subcanescens A. Gray – not accepted
  Heliomeris tenuifolia A. Gray – not accepted
  Heliopsis parvifolia A. Gray – accepted – mountain oxeye
  Heliotropium anomalum var. argenteum A. Gray – accepted – Polynesian heliotrope
  Hemicarpha occidentalis A. Gray – not accepted
  Hemitomes A. Gray – accepted – gnome plant, coneplant
  Hemitomes congestum A. Gray – accepted – coneplant, gnome plant
  Hemizonia douglasii A. Gray – not accepted
  Hemizonia fitchii A. Gray – not accepted – Fitch's tarweed
  Hemizonia floribunda A. Gray – not accepted – Tecate tarweed
  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
  Hermannia texana A. Gray – accepted – Texas hermannia, Texas burstwort
  Hesperocallis A. Gray – accepted – desert lily
  Hesperocallis undulata A. Gray – accepted – desert lily
  Hesperomannia A. Gray – accepted – island-aster
  Hesperomannia arborescens A. Gray – accepted – Lanai island-aster
  Hesperomannia arborescens var. arborescens A. Gray – not accepted
  Heuchera hallii A. Gray – accepted – Front Range alumroot
  Hibiscus arnottianus A. Gray – accepted – white rosemallow
  Hibiscus arnottianus ssp. arnottianus A. Gray – accepted – white rosemallow
  Hibiscus brackenridgei A. Gray – accepted – ma'o hau hele, Brackenridge's rosemallow
  Hibiscus brackenridgei ssp. brackenridgei A. Gray – accepted – Brackenridge's rosemallow
  Hibiscus cardiophyllus A. Gray – not accepted
  Hibiscus denudatus var. involucellatus A. Gray – 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 greenei A. Gray – accepted – Greene's hawkweed
  Hieracium lemmonii A. Gray – not accepted – Lemmon's hawkweed
  Hieracium pringlei A. Gray – accepted – Pringle's hawkweed
  Himantostemma pringlei A. Gray – not accepted
  Hoffmannseggia brachycarpa A. Gray – not accepted
  Hoffmannseggia caudata A. Gray – not accepted
  Hoffmannseggia drepanocarpa A. Gray – accepted – sicklepod holdback
  Hoffmanseggia drepanocarpa A. Gray – not accepted
  Hofmeisteria pluriseta A. Gray – not accepted
  Holacantha A. Gray – accepted
  Holacantha emoryi A. Gray – not accepted
  Horkelia bolanderi A. Gray – accepted – border horkelia, Bolander's horkelia
  Horkelia bolanderi ssp. bolanderi A. Gray – not accepted – Bolanders horkelia
  Horkelia californica var. sericea A. Gray – not accepted
  Horsfordia A. Gray – accepted – velvet mallow, velvetmallow
  Hosackia argophylla A. Gray – not accepted
  Hosackia puberula var. nana A. Gray – not accepted
  Hosackia torreyi A. Gray – not accepted
  Hosackia wrightii A. Gray – not accepted
  Houstonia angustifolia var. rigidiuscula A. Gray – not accepted
  Houstonia fasciculata A. Gray – not accepted
  Houstonia polypremoides A. Gray – not accepted
  Houstonia purpurea var. calycosa A. Gray – accepted – Venus' pride
  Houstonia wrightii A. Gray – accepted – pygmy bluet
  Howellia A. Gray – accepted
  Howellia aquatilis A. Gray – accepted – water howellia
  Hulsea algida A. Gray – accepted – Pacific hulsea, alpine hulsea
  Hulsea brevifolia A. Gray – accepted – shortleaf alpinegold
  Hulsea heterochroma A. Gray – accepted – redray alpinegold, redray hulsea
  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. vestita A. Gray – accepted – pumice alpinegold, pumice hulsea
  Hulsea vestita var. pygmaea A. Gray – not accepted
  Hydrolea affinis A. Gray – not accepted
  Hydrophyllum occidentale var. watsonii A. Gray – not accepted
  Hymenatherum neomexicanum A. Gray – not accepted
  Hymenopappus flavescens A. Gray – accepted – collegeflower, yellow woollywhite, yellow woolywhite
  Hymenopappus flavescens var. canotomentosus A. Gray – accepted – collegeflower, college flower
  Hymenopappus flavescens var. flavescens A. Gray – accepted – collegeflower
  Hymenopappus mexicanus A. Gray – accepted – Mexican woollywhite
  Hymenothrix A. Gray – accepted – thimblehead, hymenothrix
  Hymenothrix wislizeni A. Gray – accepted – Trans-Pecos thimblehead
  Hymenothrix wislizenii A. Gray – not accepted
  Hymenothrix wrightii A. Gray – accepted – Wright's thimblehead
  Hypericum canadense var. majus A. Gray – not accepted
  Ilex monticola A. Gray – not accepted
  Indigofera sphaerocarpa A. Gray – accepted – Sonoran indigo, Sonoran indigobush
  Ipomoea barbatisepala A. Gray – accepted – canyon morningglory, canyon morning-glory
  Ipomoea cardiophylla A. Gray – accepted – heartleaf morningglory, heartleaf morning-glory
  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 – Lindheimer's morningglory, blue morningglory, Lindheimer's morning-glory
  Ipomoea plummerae A. Gray – accepted – Huachuca Mountain morningglory, Huachuca morningglory, Huachuca Mountain morning-glory
  Ipomoea plummerae var. plummerae A. Gray – not accepted – Huachuca Mountain morning-glory, Huachuca Mountain morningglory
  Ipomoea thurberi A. Gray – accepted – Thurber's morningglory, Thurber's morning-glory
  Ipomoea trifida var. torreyana A. Gray – not accepted
  Ipomoea wrightii A. Gray – accepted – palmleaf morningglory, Wright's morningglory, Wright's morning-glory
  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
  Isopyrum hallii A. Gray – not accepted
  Isopyrum stipitatum A. Gray – not accepted
  Iva dealbata A. Gray – not accepted – woolly marsh-elder, woolly marshelder
  Iva hayesiana A. Gray – accepted – San Diego povertyweed
  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 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's ivesia, wire mousetail, Webber ivesia
  Ixeris stolonifera A. Gray – accepted – creeping lettuce
  Jacobinia ovata A. Gray – not accepted
  Jacquemontia pringlei A. Gray – accepted – Pringle's clustervine
  Jacquemontia sandwicensis A. Gray – not accepted
  Janusia gracilis A. Gray – not accepted – slender janusia
  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
  Keerlia effusa A. Gray – not accepted
  Kosteletzkya smilacifolia A. Gray – not accepted
  Krynitzkia utahensis A. Gray – not accepted
  Kuhnia eupatorioides var. gracillima A. Gray – not accepted
  Kuhnia shaffneri A. Gray – 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
  Lagophylla glandulosa A. Gray – accepted – glandular hareleaf
  Lagophylla glandulosa ssp. glandulosa A. Gray – not accepted – glandular hareleaf
  Laphamia angustifolia A. Gray – not accepted
  Laphamia cinerea A. Gray – not accepted
  Laphamia halimifolia A. Gray – 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
  Lasthenia glabrata var. coulteri A. Gray – not accepted
  Lathyrus torreyi A. Gray – accepted – Torrey's pea
  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 var. breviseta A. Gray – not accepted
  Leavenworthia stylosa A. Gray – accepted – cedar gladecress
  Leavenworthia torulosa A. Gray – accepted – necklace gladecress
  Lemmonia A. Gray – not accepted
  Lemmonia californica A. Gray – not accepted
  Lepachys peduncularis var. picta A. Gray – not accepted
  Lepidium alyssoides A. Gray – accepted – southern pepperweed, mesa pepperwort
  Lepidium alyssoides var. alyssoides A. Gray – not accepted – mesa pepperwort
  Lepidium dictyotum A. Gray – accepted – net pepperweed, alkali pepperweed
  Lepidium dictyotum var. acutidens A. Gray – not accepted – alkali pepperwort
  Lepidium dictyotum var. dictyotum A. Gray – not accepted – alkali pepperweed
  Lepidium sordidum A. Gray – accepted – sordid pepperweed
  Leptosyne stillmanii A. Gray – not accepted
  Lessingia glandulifera A. Gray – accepted – valley lessingia
  Lessingia glandulifera var. glandulifera A. Gray – accepted – valley lessingia, Lemmon's lessingia
  Lessingia lemmonii A. Gray – not accepted – Lemmon's vinegar-weed, Lemmon's lessingia, Lemmon's bladderpod
  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. ramulosa A. Gray – not accepted – Sonoma lessingia
  Lessingia virgata A. Gray – accepted – wand lessingia
  Lessingia virgata var. virgata A. Gray – not accepted – wand lessingia
  Leucampyx newberryi A. Gray – not accepted
  Leucophyllum minus A. Gray – accepted – big bend cenizo, Big Bend barometerbush
  Levenworthia stylosa A. Gray – not accepted
  Levenworthia torulosa A. Gray – not accepted
  Liatris garberi A. Gray – accepted – Garber's blazing star
  Linosyris arborescens A. Gray – not accepted
  Linosyris carnosa A. Gray – not accepted
  Linum adenophyllum A. Gray – not accepted
  Linum breweri A. Gray – not accepted
  Linum congestum A. Gray – not accepted
  Linum digynum A. Gray – not accepted
  Linum micranthum A. Gray – not accepted
  Linum spergulinum A. Gray – not accepted
  Lipochaeta calycosa A. Gray – not accepted
  Lipochaeta connata var. decurrens A. Gray – not accepted
  Lipochaeta heterophylla A. Gray – accepted – lavaflow nehe
  Lipochaeta remyi A. Gray – not accepted – annual nehe
  Lipochaeta subcordata A. Gray – not accepted – grassland nehe
  Lipochaeta tenuifolia A. Gray – not accepted – nehe, Waianae Range nehe
  Lippia wrightii A. Gray – not accepted
  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
  Lithospermum californicum A. Gray – accepted – California stoneseed
  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 canbyi A. Gray – accepted – Canby's lobelia
  Lobelia canbyi var. canbyi A. Gray – not accepted
  Lobelia feayana A. Gray – accepted – bay lobelia
  Lobelia gattingeri A. Gray – accepted – Gattinger's lobelia
  Lobelia gaudichaudii var. kauaensis A. Gray – not accepted
  Lobelia spicata var. hirtella A. Gray – not accepted – palespike lobelia, pale-spike lobelia
  Lobelia spicata var. parviflora A. Gray – not accepted
  Loeselia effusa A. Gray – not accepted
  Loeselia matthewsii A. Gray – not accepted
  Loeselia tenuifolia A. Gray – not accepted
  Lonicera dumosa A. Gray – not accepted
  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
  Lowellia aurea A. Gray – not accepted
  Lupinus breweri A. Gray – accepted – Brewer's lupine
  Lupinus breweri var. breweri A. Gray – accepted – Brewer's lupine
  Lupinus danaus A. Gray – not accepted
  Lupinus decumbens var. argophyllus A. Gray – 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. lyallii A. Gray – not accepted – dwarf mountain lupine, Lyall's lupine
  Lupinus lyallii var. lyallii A. Gray – accepted – dwarf mountain lupine
  Lupinus meionanthus A. Gray – not accepted – Lake Tahoe lupine, Tahoe lupine
  Lycium andersonii A. Gray – accepted – water jacket, Anderson wolfberry, Anderson's wolfberry
  Lycium andersonii var. andersonii A. Gray – accepted – water jacket, Anderson wolfberry, Anderson's wolfberry
  Lycium andersonii var. wrightii A. Gray – accepted – water jacket, Wright wolfberry
  Lycium californicum var. arizonicum A. Gray – accepted
  Lycium cooperi A. Gray – accepted – peach thorn, Cooper wolfberry, Cooper's wolfberry
  Lycium exsertum A. Gray – accepted – Arizona desert-thorn, littleleaf wolfberry
  Lycium fremontii A. Gray – accepted – Fremont's desert-thorn, Fremont wolfberry
  Lycium macrodon A. Gray – accepted – desert wolfberry
  Lycium parishii A. Gray – accepted – Parish's desert-thorn, Parish wolfberry, 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 – Torrey wolfberry, squawthorn, Torrey's wolfberry
  Lycopus lucidus var. americanus A. Gray – not accepted
  Lycopus sessilifolius A. Gray – 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
  Lysimachia hillebrandii var. angustifolia A. Gray – not accepted
  Machaeranthera canescens ssp. glabra var. glabra A. Gray – not accepted – hoary tansyaster
  Machaeranthera canescens var. glabra A. Gray – not accepted – hoary tansyaster
  Machaeranthera canescens var. latifolia A. Gray – not accepted
  Machaeranthera canescens var. tephrodes A. Gray – not accepted
  Machaeranthera canescens var. viridis A. Gray – not accepted
  Machaeranthera parviflora A. Gray – not accepted – small-flower tansy-aster, smallflower tansyaster
  Machaeranthera pruinosa A. Gray – not accepted
  Machaeranthera shastensis A. Gray – not accepted
  Malacothrix clevelandii A. Gray – accepted – Cleveland's desertdandelion, Cleveland's desert dandelion
  Malacothrix fendleri A. Gray – accepted – Fendler's desertdandelion, Fendler's desert dandelion
  Malacothrix foliosa A. Gray – accepted – leafy desertdandelion
  Malacothrix foliosa ssp. foliosa A. Gray – accepted – leafy desertdandelion
  Malacothrix platyphylla A. Gray – not accepted
  Malacothrix torreyi A. Gray – accepted – Torrey's desertdandelion, Mohave aster, Torrey's desert dandelion
  Malacothrix xanthii A. Gray – accepted
  Malvastrum A. Gray – accepted – cheeseweed, false mallow
  Malvastrum angustum A. Gray – not accepted – narrow-leaved false mallow
  Malvastrum exile A. Gray – not accepted
  Malvastrum leptophyllum A. Gray – not accepted
  Malvastrum pedatifidum A. Gray – not accepted
  Malvastrum rotundifolium A. Gray – not accepted
  Malvastrum wrightii A. Gray – not accepted
  Margaranthus lemmonii A. Gray – not accepted – Lemmon's globe berry
  Medinilla heterophylla A. Gray – accepted
  Melampodium longicorne A. Gray – accepted – Arizona blackfoot
  Melicope barbigera A. Gray – accepted – uahiapele
  Melicope cinerea A. Gray – accepted – manena
  Melicope elliptica A. Gray – accepted – leiohi'iaka
  Mellichampia A. Gray – not accepted
  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 spinescens A. Gray – accepted – spiny menodora
  Mentzelia torreyi A. Gray – accepted – Torrey's blazingstar
  Mentzelia torreyi var. torreyi A. Gray – accepted – Torrey's blazingstar
  Mentzelia tricuspis A. Gray – accepted – spinyhair stickleaf, desert blazingstar, spinyhair blazingstar
  Menziesia glabella A. Gray – not accepted
  Metastelma arizonicum A. Gray – accepted
  Metastelma blodgettii A. Gray – accepted
  Metastelma pringlei A. Gray – accepted
  Metrosideros rugosa A. Gray – accepted – lehua papa
  Micromeria brownei var. pilosiuscula A. Gray – not accepted – Browne's savory
  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 howellii A. Gray – accepted – Howell's silverpuffs
  Microseris troximoides A. Gray – not accepted
  Mimosa biuncifera var. glabrescens A. Gray – not accepted
  Mimosa borealis A. Gray – accepted – fragrant mimosa
  Mimosa borealis var. texana A. Gray – not accepted
  Mimosa grahamii A. Gray – accepted – Graham's mimosa, Graham mimosa
  Mimosa grahamii var. grahamii A. Gray – not accepted – Graham's mimosa
  Mimosa lindheimeri A. Gray – not accepted
  Mimosa malacophylla A. Gray – accepted – softleaf mimosa
  Mimulus bigelovii var. ovatus A. Gray – not accepted
  Mimulus bolanderi A. Gray – accepted – Bolander's monkeyflower
  Mimulus brevipes A. Gray – not accepted – widethroat yellow monkeyflower
  Mimulus dentatus var. gracilis A. Gray – not accepted
  Mimulus exiguus A. Gray – accepted – San Bernardino Mountain monkey-flower
  Mimulus glabratus var. ascendens A. Gray – not accepted
  Mimulus glutinosus var. brachypus A. Gray – not accepted
  Mimulus inconspicuus A. Gray – accepted – smallflower monkeyflower
  Mimulus inconspicuus var. latidens A. Gray – not accepted
  Mimulus jamesii var. texensis A. Gray – not accepted
  Mimulus laciniatus A. Gray – accepted – cutleaf monkeyflower
  Mimulus latifolius A. Gray – accepted – broadleaf monkeyflower
  Mimulus leptaleus A. Gray – accepted – least monkeyflower, slender monkeyflower
  Mimulus luteus var. alpinus A. Gray – not accepted
  Mimulus luteus var. depauperatus A. Gray – not accepted
  Mimulus luteus var. gracilis A. Gray – not accepted
  Mimulus montioides A. Gray – accepted – mountain monkeyflower, mointain monkeyflower
  Mimulus moschatus var. longiflorus A. Gray – accepted – muskflower
  Mimulus moschatus var. sessilifolius A. Gray – accepted – muskflower
  Mimulus palmeri A. Gray – accepted – Palmer's monkeyflower
  Mimulus parryi A. Gray – accepted – annual redspot monkey-flower, redspot monkeyflower, annual redspot monkeyflower
  Mimulus pulsiferae A. Gray – accepted – candelabrum monkeyflower
  Mimulus rattanii A. Gray – accepted – Rattan's monkeyflower
  Mimulus rattanii var. rattanii A. Gray – accepted – Rattan's monkeyflower
  Mimulus rubellus A. Gray – accepted – redstem monkey-flower, red monkeyflower, little redstem monkeyflower
  Mimulus subsecundus A. Gray – accepted – onesided monkeyflower
  Mimulus suksdorfii A. Gray – accepted – miniature monkey-flower, Suksdorf's monkeyflower
  Mimulus sunsecundus A. Gray – not accepted
  Mimulus torreyi A. Gray – accepted – Torrey's monkeyflower
  Mimulus whitneyi A. Gray – accepted – harlequin monkeyflower
  Mirabilis bigelovii A. Gray – not accepted – Bigelow's four-o'clock, wishbone-bush
  Mirabilis bigelovii var. bigelovii A. Gray – not accepted – desert wishbonebush, Bigelow's four o'clock, wishbone-bush
  Mirabilis californica A. Gray – not accepted – California four-o'clock, California four o'clock
  Mirabilis californica var. californica A. Gray – not accepted – California four o'clock
  Mitella breweri A. Gray – accepted – Brewer's miterwort
  Mitracarpus breviflorus A. Gray – accepted – white girdlepod
  Mohavea A. Gray – accepted
  Monarda clinopodioides A. Gray – accepted – basil beebalm
  Monarda fistulosa ssp. fistulosa var. rubra A. Gray – not accepted – wild bergamot
  Monarda fistulosa var. rubra A. Gray – accepted – wild bergamot
  Monarda punctata ssp. punctata var. lasiodonta A. Gray – not accepted – spotted beebalm
  Monarda punctata var. lasiodonta A. Gray – accepted – spotted beebalm
  Monardella breweri A. Gray – accepted – Brewer's monardella
  Monardella hypoleuca A. Gray – accepted – thickleaf monardella
  Monardella hypoleuca ssp. hypoleuca A. Gray – accepted – thickleaf monardella
  Monardella lanceolata A. Gray – accepted – mustang mountainbalm, mustang mint, mustang monardella
  Monardella lanceolata var. lanceolata A. Gray – accepted – mustang monardella, mustang mint
  Monardella lanceolata var. microcephala A. Gray – accepted – mustang monardella
  Monardella leucocephala A. Gray – accepted – Merced monardella
  Monardella linoides A. Gray – accepted – flax-leaf mountainbalm, narrowleaf monardella, flaxleaf monardella
  Monardella linoides ssp. linoides A. Gray – accepted – flax-leaf mountainbalm, flaxleaf mountainbalm, flaxleaf monardella
  Monardella macrantha A. Gray – accepted – red monardella
  Monardella macrantha ssp. macrantha A. Gray – accepted – red monardella
  Monardella nana A. Gray – accepted – yellow monardella
  Monardella nana ssp. nana A. Gray – accepted – yellow monardella
  Monardella palmeri A. Gray – accepted – Palmer's monardella
  Monardella pringlei A. Gray – accepted – Pringle's monardella, Pringle monardella
  Monnina wrightii A. Gray – accepted – blue pygmyflower, blue pygmy-flower
  Monolepis spathulata A. Gray – accepted – beaver monolepis, beaver povertyweed
  Monolopia gracilens A. Gray – accepted – woodland monolopia
  Mortonia A. Gray – accepted – saddlebush
  Mortonia greggii A. Gray – accepted – Gregg's saddlebush
  Mortonia scabrella A. Gray – accepted – Rio Grande saddlebush
  Mortonia sempervirens A. Gray – accepted – Rio Grande saddlebush
  Mortonia sempervirens ssp. sempervirens A. Gray – not accepted – Rio Grande saddlebush
  Mucuna platyphylla A. Gray – accepted
  Myoporum sandwicense A. Gray – accepted – naio
  Myoporum sandwicense var. sandwicense A. Gray – not accepted
  Myosurus minimus var. lepturus A. Gray – not accepted
  Myosurus minumus var. lepturus A. Gray – not accepted
  Nama demissa A. Gray – accepted – leafy nama, purplemat, purple mat
  Nama demissa var. demissa A. Gray – accepted – purplemat, purple mat
  Nama demissum A. Gray – not accepted – purple mat, leafy nama, purplemat
  Nama demissum var. demissum A. Gray – not accepted – purplemat, purple mat
  Nama havardii A. Gray – accepted – Havard's fiddleleaf
  Nama hispida A. Gray – accepted – bristly nama, purple mat
  Nama hispidum A. Gray – not accepted – purple mat, bristly nama
  Nama lobbii A. Gray – accepted – woolly nama, Lobb's fiddleleaf
  Nama rothrockii A. Gray – accepted – baldhead nama, Rothrock's fiddleleaf
  Nama sandwicense A. Gray – not accepted – hinahina kahakai
  Nama sandwicensis A. Gray – accepted – hinahina kahakai
  Nama sandwicese A. Gray – not accepted
  Nama stenocarpa A. Gray – accepted – mud fiddleleaf
  Nama stenocarpum A. Gray – not accepted – mud fiddleleaf
  Nasturtium lacustre A. Gray – not accepted
  Nasturtium sphaerocarpum A. Gray – not accepted
  Nemacladus longiflorus A. Gray – accepted – longflower threadplant
  Nemacladus longiflorus var. longiflorus A. Gray – accepted – long-flower threadplant, longflower threadplant
  Nemophila breviflora A. Gray – accepted – baby blueeyes, Great Basin blue-eyes, basin nemophila
  Nesaea longipes A. Gray – accepted – stalkflower
  Neviusia A. Gray – accepted – snow-wreath
  Neviusia alabamensis A. Gray – accepted – Alabama snow-wreath
  Nicolletia A. Gray – accepted – hole-in-the-sand plant, nicolletia
  Nicolletia edwardsii A. Gray – accepted – Edwards' hole-in-the-sand plant, Edwards' hole in the sand plant
  Nicolletia occidentalis A. Gray – accepted – Mojave hole-in-the-sand plant
  Nicotiana bigelovii var. wallacei A. Gray – not accepted
  Nicotiana clevelandii A. Gray – accepted – Cleveland's tobacco
  Nicotiana palmeri A. Gray – not accepted
  Nothocestrum A. Gray – accepted – aiea
  Nothocestrum breviflorum A. Gray – accepted – `aiea, smallflower aiea
  Nothocestrum brevifolium A. Gray – not accepted
  Nothocestrum latifolium A. Gray – accepted – 'aiea, broadleaf aiea
  Nothocestrum longifolium A. Gray – accepted – longleaf aiea
  Oenothera biennis var. oakesiana A. Gray – not accepted
  Oenothera brachycarpa A. Gray – accepted – shortfruit evening-primrose, shortfruit eveningprimrose, shortfruit evening primrose
  Oenothera brevipes A. Gray – not accepted
  Oenothera chamaenerioides A. Gray – not accepted
  Oenothera fendleri A. Gray – not accepted
  Oenothera greggii A. Gray – not accepted
  Oenothera greggii var. pubescens A. Gray – not accepted
  Oenothera missouriensis var. incana A. Gray – not accepted
  Oenothera primiveris A. Gray – accepted – desert evening-primrose, desert eveningprimrose, desert evening primrose
  Oenothera primiveris ssp. primiveris A. Gray – not accepted – desert evening primrose, desert evening-primrose, desert eveningprimrose
  Oenothera tubicula A. Gray – accepted – Texas sundrops
  Oenothera tubicula ssp. tubicula A. Gray – accepted – Texas sundrops
  Oldenlandia greenei A. Gray – not accepted
  Olneya A. Gray – accepted
  Olneya tesota A. Gray – accepted – desert ironwood, ironwood
  Omphalodes aliena A. Gray – accepted – Mexican navelwort
  Orthocarpus attenuatus A. Gray – not accepted
  Orthocarpus erianthus var. roseus A. Gray – not accepted
  Orthocarpus faucibarbatus A. Gray – not accepted
  Orthocarpus faucibarbatus var. faucibarbatus A. Gray – not accepted – bearded owlclover
  Orthocarpus lasiorhynchus A. Gray – not accepted
  Orthocarpus pachystachys A. Gray – not accepted
  Orthocarpus pachystachyus A. Gray – accepted – Shasta orthocarpus, Shasta owl's-clover
  Orthocarpus purpurascens var. palmeri A. Gray – not accepted
  Osmunda cinnamomea var. frondosa A. Gray – not accepted
  Oxalis dichondrifolia A. Gray – accepted – peonyleaf woodsorrel
  Oxalis drummondii A. Gray – accepted – Drummond's woodsorrel
  Oxalis wrightii A. Gray – not accepted
  Oxytheca trilobata A. Gray – not accepted – threelobe oxytheca
  Oxytropis lambertii var. bigelovii A. Gray – accepted – purple locoweed
  Oxytropis monticola A. Gray – not accepted – yellowflower locoweed, yellow-flower locoweed
  Oxytropis oreophila A. Gray – accepted – mountain oxytrope, mountain locoweed, roundleaf crazyweed
  Oxytropis oreophila var. oreophila A. Gray – accepted – mountain oxytrope, mountain locoweed
  Oxytropis parryi A. Gray – accepted – Parry's oxytrope, Parry pointvetch, Parry's crazyweed
  Oxytropis podocarpa A. Gray – accepted – stalkpod locoweed
  Palafoxia feayi A. Gray – accepted – Feay's palafox
  Palmerella A. Gray – accepted
  Palmerella debilis A. Gray – accepted
  Palmerella debilis ssp. debilis A. Gray – accepted
  Panicum nitidum var. crassifolium A. Gray – not accepted
  Panicum nitidum var. villosum A. Gray – not accepted
  Panicum xanthophysum A. Gray – not accepted
  Papaver californicum A. Gray – accepted – western poppy
  Parishella A. Gray – not accepted
  Parishella californica A. Gray – not accepted – Mojave dwarf
  Parnassia palustris var. californica A. Gray – not accepted
  Paronychia pulvinata A. Gray – accepted – Rocky Mountain nailwort
  Paronychia pulvinata var. pulvinata A. Gray – not accepted – Rocky Mountain nailwort
  Parthenice A. Gray – accepted – parthenice
  Parthenice mollis A. Gray – accepted – annual monsterwort
  Parthenium argentatum A. Gray – accepted – guayule
  Parthenium confertum A. Gray – accepted – Gray's feverfew, gray feverfew
  Parthenium confertum var. confertum A. Gray – not accepted – Gray's feverfew
  Parthenium hysterophorus var. lyratum A. Gray – not accepted
  Pavonia wrightii A. Gray – not accepted
  Paxistima canbyi A. Gray – accepted – Canby's mountain-lover
  Pectis imberbis A. Gray – accepted – beardless chinchweed, beardless cinchweed
  Pectis longipes A. Gray – accepted – longstalk chinchweed, mat cinchweed, longstalk cinchweed
  Pectocarya setosa A. Gray – accepted – bristly combseed, moth combseed
  Pedicularis attolens A. Gray – not accepted
  Pedicularis attollens A. Gray – accepted – little elephantshead
  Pedicularis attollens ssp. attollens A. Gray – accepted – little elephantshead
  Pedicularis canbyi A. Gray – not accepted
  Pedicularis centranthera A. Gray – accepted – dwarf lousewort
  Pedicularis howellii A. Gray – accepted – Howell lousewort, Howell's lousewort
  Pedicularis parryi A. Gray – accepted – Parry's cinchweed, Parry's lousewort
  Pedicularis parryi ssp. parryi A. Gray – accepted – Parry's lousewort
  Pedicularis procera A. Gray – not accepted – gray lousewort, giant lousewort
  Pedicularis semibarbata A. Gray – accepted – bearded lousewort, pinewoods lousewort
  Pedicularis semibarbata var. semibarbata A. Gray – accepted – pinewoods lousewort
  Pedicularis sudetica var. scopulorum A. Gray – not accepted
  Peganum mexicanum A. Gray – accepted – garbancillo
  Pelea A. Gray – not accepted
  Pelea clusiifolia A. Gray – not accepted
  Pelea clusiifolia var. clusiifolia A. Gray – not accepted
  Pelea oblongifolia A. Gray – not accepted
  Pelea oblongifoloa A. Gray – not accepted
  Pelea rotundifolia A. Gray – not accepted
  Pelea volcanica A. Gray – not accepted
  Penstemon azureus var. angustissimus A. Gray – accepted – azure penstemon
  Penstemon azureus var. parvulus A. Gray – not accepted – azure penstemon
  Penstemon barbatus var. puberulus A. Gray – not accepted
  Penstemon barbatus var. trichander A. Gray – accepted – Torrey's penstemon
  Penstemon barrettiae A. Gray – accepted – Barrett's beardtongue
  Penstemon bridgesii A. Gray – not accepted
  Penstemon caesius A. Gray – accepted – San Bernardino beardtongue
  Penstemon caespitosus var. suffruticosus A. Gray – not accepted
  Penstemon cleavelandii A. Gray – not accepted
  Penstemon cleavelandii var. cleavelandii A. Gray – not accepted
  Penstemon clevelandii A. Gray – accepted – Cleveland's beardtongue
  Penstemon clevelandii ssp. clevelandii A. Gray – not accepted – Cleveland's beardtongue
  Penstemon clevelandii var. clevelandii A. Gray – accepted – Cleveland's beardtongue
  Penstemon comarrhenus A. Gray – accepted – dusty penstemon, dusty beardtongue
  Penstemon cusickii A. Gray – accepted – Cusick's beardtongue
  Penstemon dasyphyllus A. Gray – accepted – purple penstemon, Cochise beardtongue
  Penstemon eatonii A. Gray – accepted – Eaton's penstemon, firecracker penstemon
  Penstemon eatonii ssp. eatonii A. Gray – accepted – Eaton's penstemon, firecracker penstemon
  Penstemon eatonii var. eatonii A. Gray – not accepted – beardtongue
  Penstemon gairdneri var. oreganus A. Gray – accepted – Gairdner's beardtongue
  Penstemon gracilentus A. Gray – accepted – slender penstemon
  Penstemon hallii A. Gray – accepted – Hall's beardtongue
  Penstemon harbourii A. Gray – accepted – Harbour's beardtongue
  Penstemon harvardii A. Gray – not accepted
  Penstemon havardii A. Gray – accepted – Big Bend beardtongue
  Penstemon heterodoxus A. Gray – accepted – Sierra penstemon, Sierra beardtongue
  Penstemon heterodoxus ssp. heterodoxus A. Gray – not accepted – Sierran beardtongue
  Penstemon heterodoxus var. heterodoxus A. Gray – accepted – Sierra beardtongue
  Penstemon humilis var. brevifolius A. Gray – accepted – low beardtongue
  Penstemon laetus A. Gray – accepted – mountain blue penstemon
  Penstemon laetus ssp. laetus A. Gray – not accepted – mountain blue penstemon
  Penstemon laetus var. laetus A. Gray – accepted – beardtongue
  Penstemon lemmonii A. Gray – not accepted
  Penstemon linarioides A. Gray – accepted – creeping penstemon, toadflax penstemon
  Penstemon linarioides ssp. linarioides A. Gray – accepted – toadflax penstemon, toadflax beardtongue
  Penstemon linarioides var. sileri A. Gray – not accepted
  Penstemon lyallii A. Gray – accepted – Lyall's beardtongue
  Penstemon microphyllus A. Gray – not accepted
  Penstemon miser A. Gray – accepted – Malheur penstemon
  Penstemon newberryi A. Gray – accepted – pride-of-the-mountains, mountain pride
  Penstemon newberryi ssp. newberryi A. Gray – not accepted – Newberry's penstemon, mountain pride
  Penstemon newberryi var. newberryi A. Gray – accepted – beardtongue
  Penstemon nudiflorus A. Gray – accepted – Flagstaff beardtongue
  Penstemon palmeri A. Gray – accepted – Palmer's penstemon
  Penstemon palmeri var. palmeri A. Gray – accepted – Palmer's penstemon
  Penstemon rattanii A. Gray – accepted – Rattan's beardtongue
  Penstemon rattanii ssp. rattanii A. Gray – not accepted – Rattan's beardtongue
  Penstemon rattanii var. minor A. Gray – not accepted
  Penstemon rattanii var. rattanii A. Gray – accepted – beardtongue
  Penstemon rothrockii A. Gray – not accepted
  Penstemon stenophyllus A. Gray – accepted – Sonoran beardtongue
  Penstemon virgatus A. Gray – accepted – upright blue beardtongue
  Penstemon virgatus var. virgatus A. Gray – accepted – upright blue beardtongue
  Penstemon wardii A. Gray – accepted – Ward's beardtongue, Ward beardtongue
  Penstemon watsonii A. Gray – accepted – Watson's beardtongue, Watson's penstemon
  Penstemon whippleanus A. Gray – accepted – dark beardtongue, Whipple's penstemon
  Pentachaeta exilis var. aphantochaeta A. Gray – not accepted
  Pentachaeta exilis var. discoidea A. Gray – not accepted
  Pentachaeta lyonii A. Gray – accepted – Lyon's pygmydaisy, Lyon's pentachaeta
  Pentachaeta orcuttii A. Gray – not accepted
  Perezia nana A. Gray – not accepted
  Perezia thurberi A. Gray – not accepted
  Perezia wrightii A. Gray – not accepted
  Pericome A. Gray – accepted – pericome
  Pericome caudata A. Gray – accepted – mountain tail-leaf, mountain leaftail, mountain taper leaf
  Perityle aglossa A. Gray – accepted – bluff rockdaisy
  Perityle coronopifolia A. Gray – accepted – crowfoot rockdaisy, Arizona rockdaisy
  Perityle microglossa var. effusa A. Gray – not accepted
  Perityle parryi A. Gray – accepted – Parry's rockdaisy, heartleaf rockdaisy
  Perrottetia sandwicensis A. Gray – accepted – olomea
  Petalonyx A. Gray – accepted – sandpaperplant, sandpaper plant
  Petalonyx parryi A. Gray – accepted – Parry's sandpaperplant, Parry's sandpaper plant
  Petalonyx thurberi A. Gray – accepted – sandpaper plant, Thurber's sandpaperplant, Thurber's sandpaper plant
  Petalonyx thurberi ssp. thurberi A. Gray – accepted – Thurber's sandpaper plant, Thurber's sandpaperplant
  Petalostemon exilis A. Gray – not accepted
  Petalostemon foliosus A. Gray – not accepted
  Petalostemon searlsiae A. Gray – not accepted
  Petalostemon tenuifolius A. Gray – not accepted
  Petalostemum foliosum A. Gray – not accepted
  Peteria A. Gray – accepted
  Peteria scoparia A. Gray – accepted – rush peteria
  Peucephyllum A. Gray – accepted – pygmycedar, pygmy cedar
  Peucephyllum schottii A. Gray – accepted – Schott's pygmycedar, pygmy cedar, pygmycedar
  Phacelia affinis A. Gray – accepted – limestone scorpion-weed, limestone scorpionweed, purplebell phacelia, limestone phacelia
  Phacelia arizonica A. Gray – accepted – Arizona scorpion-weed, Arizona scorpionweed, Arizona phacelia
  Phacelia bolanderi A. Gray – accepted – Bolander's phacelia
  Phacelia breweri A. Gray – accepted – Brewer's phacelia
  Phacelia campanularia A. Gray – accepted – desertbells
  Phacelia campanularia ssp. campanularia A. Gray – accepted – desertbells
  Phacelia cephalotes A. Gray – accepted – scorpion-weed, virgin phacelia
  Phacelia congesta var. dissecta A. Gray – not accepted
  Phacelia davidsonii A. Gray – accepted – Davidson's phacelia
  Phacelia demissa A. Gray – accepted – Intermountain scorpionweed, intermountain scorpion-weed, Intermountain phacelia
  Phacelia demissa var. demissa A. Gray – accepted – Intermountain phacelia, intermountain scorpion-weed
  Phacelia glechomifolia A. Gray – accepted – pennyroyal-leaf scorpion-weed, pennyroyal leaf phacelia
  Phacelia grisea A. Gray – accepted – Santa Lucia phacelia
  Phacelia lemmonii A. Gray – accepted – Lemmon's scorpion-weed, Lemmon's phacelia
  Phacelia mohavensis A. Gray – accepted – Mojave phacelia
  Phacelia mohavensis var. exilis A. Gray – not accepted
  Phacelia nohavensis A. Gray – not accepted
  Phacelia pachyphylla A. Gray – accepted – blacktack phacelia
  Phacelia parishii A. Gray – accepted – Parish's phacelia
  Phacelia pedicellata A. Gray – accepted – pedicellate scorpion-weed, pedicellate phacelia
  Phacelia platyloba A. Gray – accepted – broadlobe phacelia
  Phacelia pringlei A. Gray – accepted – Pringle's phacelia
  Phacelia procera A. Gray – accepted – tall phacelia
  Phacelia pulchella A. Gray – accepted – beautiful scorpionweed, beautiful phacelia
  Phacelia pulchella var. pulchella A. Gray – accepted – beautiful phacelia, beautiful scorpion-weed, beautiful scorpionweed
  Phacelia rattanii A. Gray – accepted – rattan phacelia, Rattan's phacelia
  Phacelia saxicola A. Gray – accepted – stonecrop scorpion-weed, rock phacelia, stonecrop phacelia
  Phacelia whitlavia A. Gray – not accepted
  Phalacroseris A. Gray – accepted – mock dandelion
  Phalacroseris bolanderi A. Gray – accepted – Bolander's mock dandelion
  Phalacroseris bolanderi var. bolanderi A. Gray – not accepted – Bolander's mock dandelion
  Phaseolus acutifolius A. Gray – accepted – tepary bean
  Phaseolus acutifolius var. acutifolius A. Gray – accepted – tepary bean
  Phaseolus acutifolius var. tenuifolius A. Gray – accepted – tepary bean
  Phaseolus angustissimus A. Gray – accepted – slimleaf bean, narrowleaf bean
  Phaseolus wrightii A. Gray – not accepted
  Phaulothamnus A. Gray – accepted – snake-eyes
  Phaulothamnus spinescens A. Gray – accepted – snake-eyes, devilqueen
  Phelipaea tuberosa A. Gray – not accepted
  Pherotrichis balbisii A. Gray – not accepted
  Pherotrichis schaffneri A. Gray – accepted
  Philadelphus microphyllus A. Gray – accepted – littleleaf mockorange, littleleaf mock orange
  Philadelphus microphyllus var. microphyllus A. Gray – accepted – littleleaf mockorange, littleleaf mock orange
  Philadelphus serpyllifolius A. Gray – accepted – thyme-leaf mock orange, littleleaf mockorange, thymeleaf mock orange
  Phlox dolichantha A. Gray – accepted – Big Bear Valley phlox, Bear Valley Phlox
  Phlox pilosa var. detonsa A. Gray – not accepted
  Phlox stellaria A. Gray – not accepted
  Phoradendron juniperinum A. Gray – accepted – incense cedar mistletoe, juniper mistletoe
  Phoradendron juniperinum ssp. juniperinum A. Gray – not accepted – juniper mistletoe
  Phyllostegia brevidens A. Gray – accepted – Mauna Kea phyllostegia
  Phyllostegia brevidens var. ambigua A. Gray – not accepted
  Phyllostegia parviflora var. glabriuscula A. Gray – accepted – smallflower phyllostegia
  Phyllostegia stachyoides A. Gray – accepted – Maui phyllostegia
  Phyllostegia velutinara var. glabriuscula A. Gray – not accepted
  Physalis fendleri A. Gray – not accepted
  Physalis fendleri var. cordifolia A. Gray – not accepted
  Physalis hederifolia A. Gray – accepted – ivyleaf groundcherry, ivyleaf ground cherry
  Physalis hederifolia var. hederifolia A. Gray – accepted – ivyleaf groundcherry
  Physalis hederifolia var. puberula A. Gray – not accepted
  Physalis palmeri A. Gray – not accepted
  Physalis wrightii A. Gray – not accepted – sharpleaf groundcherry, Wright groundcherry
  Physaria newberryi A. Gray – accepted – Newberry's twinpod
  Physaria newberryi ssp. newberryi A. Gray – accepted – Newberry's twinpod
  Physaria newberryi var. newberryi A. Gray – not accepted – Newberry's twinpod
  Physostegia brevidens A. Gray – not accepted
  Physostegia stachyoides A. Gray – not accepted
  Pilostyles thurberi A. Gray – accepted – stemsucker, Thurber's stemsucker, Thurber's pilostyles
  Pinguicula vulgaris var. americana A. Gray – not accepted
  Pittosporum confertiflorum A. Gray – accepted – ho'awa
  Plagiobothrys arizonicus var. catalinensis A. Gray – not accepted
  Plagiobothrys glomeratus A. Gray – accepted – cluster popcornflower, clustered popcornflower
  Plagiobothrys hispidus A. Gray – accepted – Cascade popcornflower
  Plagiobothrys jonesii A. Gray – accepted – Jones' popcornflower, Mojave popcornflower
  Plantago bigelovii A. Gray – accepted – coast plantain
  Plantago bigelovii ssp. bigelovii A. Gray – accepted – coast plantain
  Plantago pachyphylla A. Gray – accepted – Maui plantain
  Plantago pachyphylla var. maviensis A. Gray – not accepted
  Plantago princeps var. hirtella A. Gray – not accepted
  Plantago princeps var. laxiflora A. Gray – not accepted – ale
  Plantago princeps var. laxifolia A. Gray – accepted
  Plantago tweedyi A. Gray – accepted – Tweedy's plantain
  Pleucephyllum A. Gray – not accepted
  Pleucephyllum schottii A. Gray – not accepted
  Pleuricospora A. Gray – accepted – pinesap
  Pleuricospora fimbriolata A. Gray – accepted – fringed pinesap, sierra sap
  Plummera A. Gray – not accepted – plummera
  Plummera floribunda A. Gray – not accepted
  Poa alsodes A. Gray – accepted – grove bluegrass
  Poa caesia var. strictior A. Gray – not accepted
  Poa sylvestris A. Gray – accepted – woodland bluegrass
  Pogogyne nudiuscula A. Gray – accepted – Otay Mesa mint
  Polemonium carneum A. Gray – accepted – royal Jacob's-ladder
  Polemonium confertum A. Gray – accepted – Rocky Mountain Jacob's-ladder
  Polemonium foliosissimum A. Gray – accepted – towering Jacob's-ladder, leafy polemonium, leafy Jacob's-ladder
  Polemonium foliosissimum var. foliosissimum A. Gray – accepted – towering Jacob's-ladder
  Poliomintha A. Gray – accepted – rosemarymint, rosemary mint, rosemary-mint
  Poliomintha glabrescens A. Gray – accepted – leafy rosemarymint, rosemary-mint
  Poliomintha longiflora A. Gray – accepted
  Polionintha A. Gray – not accepted
  Polionintha glabrescens A. Gray – not accepted
  Polionintha longiflora A. Gray – not accepted
  Polygala acanthoclada A. Gray – accepted – desert polygala, thorny polygala
  Polygala curtissii A. Gray – accepted – Curtiss' milkwort
  Polygala hemipterocarpa A. Gray – accepted – winged milkwort
  Polygala lindheimeri A. Gray – accepted – shrubby milkwort
  Polygala lindheimeri var. lindheimeri A. Gray – accepted – shrubby milkwort
  Polygala macradenia A. Gray – accepted – purple milkwort, glandleaf milkwort
  Polygala ovatifolia A. Gray – accepted – eggleaf milkwort
  Polygala puberula A. Gray – not accepted
  Polygonum hartwrightii A. Gray – not accepted
  Polymnia canadensis var. radiata A. Gray – not accepted
  Porophyllum greggii A. Gray – accepted – Gregg's poreleaf
  Porophyllum scoparium A. Gray – accepted – Trans-Pecos poreleaf, shrubby poreleaf
  Portulaca parvula A. Gray – not accepted
  Portulaca sclerocarpa A. Gray – accepted – po'e, 'ihi makole
  Potentilla crinata A. Gray – not accepted
  Potentilla crinita A. Gray – accepted – bearded cinquefoil
  Potentilla crinita var. crinita A. Gray – not accepted – bearded cinquefoil
  Potentilla newberryi A. Gray – accepted – Newberry's cinquefoil
  Potentilla thurberi A. Gray – accepted – scarlet cinquefoil
  Potentilla thurberi var. thurberi A. Gray – accepted – scarlet cinquefoil, Thurber's cinquefoil
  Prenanthes alata var. sagittata A. Gray – not accepted
  Prenanthes racemosa ssp. racemosa var. pinnatifida A. Gray – not accepted – purple rattlesnakeroot
  Prenanthes racemosa var. pinnatifida A. Gray – not accepted
  Primula japonica A. Gray – accepted – Japanese primrose
  Primula parryi A. Gray – accepted – brook primrose, bog primrose, Parry's primrose
  Primula suffrutescens A. Gray – accepted – Sierra primrose
  Prunus andersonii A. Gray – accepted – Anderson's peachbrush, desert peach
  Psathyrotes A. Gray – accepted – turtleback, psathyrotes
  Psathyrotes pilifera A. Gray – accepted – hairybeast turtleback, hairy-beast turtleback, hairybeast brittlestem
  Psathyrotes scaposa A. Gray – not accepted – naked turtleback
  Pseudobahia bahiifolia var. pinnatifida A. Gray – not accepted
  Psilactis A. Gray – accepted – tansyaster, psilactis
  Psilactis asteroides A. Gray – accepted – New Mexico tansyaster, New Mexico tansy-aster, hoary aster
  Psilocarphus chilensis A. Gray – accepted – slender woollyheads
  Psoralea cyphocalyx A. Gray – not accepted
  Psoralea hypogaea var. scaposa A. Gray – not accepted
  Psoralea micrantha A. Gray – not accepted
  Psychotria insularum A. Gray – accepted – island wild coffee
  Pugiopappus bigelovii A. Gray – not accepted
  Pycnanthemum leptodon A. Gray – not accepted
  Pyrola dentata var. integra A. Gray – not accepted
  Pyrrhopappus rothrockii A. Gray – accepted
  Rafinesquia neomexicana A. Gray – accepted – New Mexico plumeseed, desert chicory
  Raillardella muirii A. Gray – not accepted
  Raillardella rothrockii A. Gray – not accepted
  Raillardia argentea A. Gray – not accepted
  Railliardia arborea A. Gray – not accepted
  Railliardia ciliolata var. juniperoides A. Gray – not accepted
  Railliardia latifolia A. Gray – not accepted
  Railliardia menziesii A. Gray – not accepted
  Railliardia platyphylla A. Gray – not accepted
  Railliardia scabra var. leiophylla A. Gray – not accepted
  Railliardia struthioloides A. Gray – not accepted
  Ranunculus abortivus var. harveyi A. Gray – not accepted
  Ranunculus acriformis A. Gray – accepted – sharpleaf buttercup
  Ranunculus acriformis var. acriformis A. Gray – accepted – autumn buttercup, sharpleaf buttercup
  Ranunculus adoneus A. Gray – accepted – alpine buttercup
  Ranunculus adoneus var. adoneus A. Gray – not accepted – alpine buttercup
  Ranunculus alismifolius var. alismellus A. Gray – accepted – plantainleaf buttercup
  Ranunculus andersonii A. Gray – accepted – pink buttercup, Anderson's buttercup
  Ranunculus andersonii var. andersonii A. Gray – not accepted – Anderson's buttercup
  Ranunculus arizonicus var. subaffinis A. Gray – not accepted
  Ranunculus hawaiensis A. Gray – accepted – makou, Hawai'ian buttercup
  Ranunculus hydrocharoides A. Gray – accepted – frogbit buttercup
  Ranunculus hydrocharoides var. hydrocharoides A. Gray – not accepted – frogbit buttercup
  Ranunculus hystriculus A. Gray – accepted – waterfall false buttercup
  Ranunculus lemmonii A. Gray – not accepted
  Ranunculus macauleyi A. Gray – accepted – Rocky Mountain buttercup
  Ranunculus macauleyi var. macauleyi A. Gray – not accepted – MaCauley's buttercup, Rocky Mountain buttercup
  Ranunculus mauiensis A. Gray – accepted – makou, Maui buttercup
  Ranunculus occidentalis var. rattanii A. Gray – not accepted
  Ranunculus orthorhynchus var. platyphyllis A. Gray – not accepted
  Ranunculus orthorhynchus var. platyphyllus A. Gray – accepted
  Ranunculus oxynotus A. Gray – not accepted
  Ranunculus suksdorfii A. Gray – not accepted – Suksdorf's buttercup
  Ranunculus triternatus A. Gray – accepted – obscure buttercup
  Reverchonia A. Gray – not accepted
  Reverchonia arenaria A. Gray – not accepted – sand reverchonia
  Reynoldsia A. Gray – not accepted
  Reynoldsia sandwicensis A. Gray – not accepted – `ohe makai, `ohe
  Rhododendron chapmanii A. Gray – not accepted – Chapman's rhododendron
  Rhododendron vaseyi A. Gray – accepted – pink-shell azalea, pinkshell azalea
  Rhus copallina var. lanceolata A. Gray – not accepted
  Rhus copallinum var. lanceolata A. Gray – accepted
  Rhus sandwicensis A. Gray – accepted – neneleau
  Rhynchospora baldwinii A. Gray – accepted – Baldwin's beaksedge
  Rhynchospora cephalantha A. Gray – accepted – bunched beaksedge
  Rhynchospora cephalantha var. cephalantha A. Gray – not accepted – bunched beaksedge
  Rhynchospora filifolia A. Gray – accepted – threadleaf beaksedge
  Rhynchospora gracilenta A. Gray – accepted – slender beaksedge
  Rhynchospora megalocarpa A. Gray – accepted – sandyfield beaksedge
  Rhynchospora oligantha A. Gray – accepted – featherbristle beaksedge
  Rhynchospora patula A. Gray – not accepted
  Rhynchospora semiplumosa A. Gray – not accepted
  Rhynchospora torreyana A. Gray – accepted – Torrey's beaksedge
  Ribes lacustre var. molle A. Gray – not accepted
  Ribes lacustre var. parvulum A. Gray – not accepted
  Ribes leptanthum A. Gray – accepted – trumpet gooseberry
  Ribes lobbii A. Gray – accepted – gummy gooseberry
  Ribes viburnifolium A. Gray – accepted – island gooseberry
  Riddellia cooperi A. Gray – not accepted
  Riddellia tagetina var. sparsiflora A. Gray – not accepted
  Rigiopappus A. Gray – accepted – rigiopappus
  Rigiopappus leptocladus A. Gray – accepted – wireweed
  Robinia neomexicana A. Gray – accepted – New Mexico locust
  Robinia neomexicana var. neomexicana A. Gray – accepted – New Mexico locust
  Rodgersia A. Gray – accepted
  Rosa pisocarpa A. Gray – accepted – cluster rose
  Rosa pisocarpa ssp. pisocarpa A. Gray – accepted – cluster rose
  Rothrockia A. Gray – not accepted
  Rothrockia cordifolia A. Gray – not accepted
  Rubus hawaiensis A. Gray – accepted – Hawai'i blackberry
  Rubus lasiococcus A. Gray – accepted – roughfruit berry
  Rubus macraei A. Gray – accepted – 'akala
  Rubus neomexicanus A. Gray – accepted – New Mexico raspberry
  Rudbeckia californica A. Gray – accepted – California coneflower
  Rudbeckia californica var. californica A. Gray – not accepted – California coneflower
  Rudbeckia laciniata var. humilis A. Gray – accepted – greenhead coneflower, cutleaf coneflower
  Rudbeckia mohrii A. Gray – accepted – Mohr's coneflower
  Rudbeckia montana A. Gray – accepted – montane coneflower
  Ruellia ciliosa var. longiflora A. Gray – not accepted
  Ruellia parryi A. Gray – accepted – Parry's wild petunia
  Ruellia strepens var. cleistantha A. Gray – not accepted
  Ruellia tuberosa var. occidentalis A. Gray – not accepted
  Rumex orbiculatus A. Gray – not accepted – greater water dock
  Rumex orbiculatus var. orbiculatus A. Gray – not accepted – greater water dock
  Sabatia boykinii A. Gray – not accepted
  Sabatia gracilis var. grandiflora A. Gray – not accepted
  Sabatia palmeri A. Gray – not accepted
  Sagina maxima A. Gray – accepted – stickystem pearlwort
  Sagina maxima ssp. maxima A. Gray – accepted – stickystem pearlwort
  Salvia arizonica A. Gray – accepted – Arizona sage, desert indigo sage
  Salvia chapmanii A. Gray – accepted – Chapman's sage
  Salvia engelmannii A. Gray – accepted – Engelmann's sage
  Salvia greggii A. Gray – accepted – autumn sage
  Salvia henryi A. Gray – accepted – crimson sage
  Salvia lemmonii A. Gray – accepted – red sage, Lemmon's sage
  Salvia lycioides A. Gray – accepted – canyon sage
  Salvia microphylla var. wislizeni A. Gray – not accepted
  Salvia parryi A. Gray – accepted – Parry's sage
  Sambucus canadensis var. laciniata A. Gray – not accepted – Florida elder
  Sambucus melanocarpa A. Gray – not accepted
  Sanicula sandwicensis A. Gray – accepted – Hawai'i blacksnakeroot
  Santalum pyrularium A. Gray – accepted
  Sanvitalia abertii A. Gray – accepted – Albert's creeping zinnia
  Sanvitalia angustifolia A. Gray – not accepted
  Sartwellia A. Gray – accepted – glowwort, sartwellia
  Sartwellia flaveriae A. Gray – accepted – threadleaf glowwort
  Saxifraga bryophora A. Gray – not accepted – bud saxifrage
  Saxifraga bryophora var. bryophora A. Gray – not accepted – bud saxifrage
  Saxifraga careyana A. Gray – not accepted – golden eye saxifrage
  Saxifraga caroliniana A. Gray – not accepted – Carolina saxifrage, Gray's saxifrage
  Saxifraga chrysantha A. Gray – accepted – golden saxifrage, goldbloom saxifrage
  Schaefferia cuneifolia A. Gray – accepted – desert yaupon
  Schiedea diffusa A. Gray – accepted – spreading schiedea
  Schiedea diffusa ssp. diffusa A. Gray – accepted
  Schiedea hookeri A. Gray – accepted – sprawling schiedea
  Schiedea spergulina A. Gray – accepted – canyon schiedea
  Schiedea spergulina var. spergulina A. Gray – not accepted – canyon schiedea
  Schkuhria wislizeni A. Gray – not accepted – Wislizenus' false threadleaf
  Schkuhria wislizeni var. wislizeni A. Gray – not accepted – Wislizenus' false threadleaf
  Schkuhria wislizenii A. Gray – not accepted
  Schoenocaulon A. Gray – accepted – feathershank
  Schoenocaulon drummondii A. Gray – not accepted – green feathershank
  Scirpus clintonii A. Gray – not accepted – clinton bulrush, scirpe de Clinton
  Scirpus cringer A. Gray – not accepted
  Scirpus criniger A. Gray – not accepted
  Scirpus hallii A. Gray – not accepted
  Scirpus olneyi A. Gray – not accepted
  Scirpus smithii A. Gray – not accepted – smith's bulrush, scirpe de Smith
  Scirpus wolfii A. Gray – not accepted
  Scrophularia coccinea A. Gray – not accepted
  Scutellaria angustifolia var. canescens A. Gray – not accepted
  Scutellaria bolanderi A. Gray – accepted – Sierra skullcap
  Scutellaria bolanderi ssp. bolanderi A. Gray – accepted – Sierra skullcap
  Scutellaria brevifolia A. Gray – not accepted
  Scutellaria californica A. Gray – accepted – California skullcap
  Scutellaria nana A. Gray – accepted – dwarf skullcap
  Scutellaria wrighti A. Gray – not accepted
  Scutellaria wrightii A. Gray – accepted – resin-dot skullcap, resinous skullcap, Skullcap, Wright's skullcap
  Sedum nevii A. Gray – accepted – Nevius' stonecrop
  Sedum obtusatum A. Gray – accepted – Sierra stonecrop, Sierran stonecrop
  Sedum obtusatum ssp. obtusatum A. Gray – not accepted – Sierran stonecrop, Sierra stonecrop
  Sedum obtusatum var. obtusatum A. Gray – accepted – Sierra stonecrop
  Sedum rhodanthum A. Gray – not accepted – redpod stonecrop
  Sedum wrightii A. Gray – accepted – Wright's stonecrop
  Sedum wrightii ssp. wrightii A. Gray – accepted – Wright's stonecrop
  Selinocarpus A. Gray – not accepted – moonpod
  Selinocarpus chenopodioides A. Gray – not accepted
  Selinocarpus diffusus A. Gray – not accepted – moonpod, spreading moonpod
  Senecio amplectens A. Gray – accepted – showy alpine ragwort, showy alpine groundsel, alpine groundsel
  Senecio amplectens var. amplectens A. Gray – accepted – showy alpine ragwort
  Senecio amplectens var. taraxacoides A. Gray – not accepted
  Senecio aureus var. werneriifolius A. Gray – not accepted
  Senecio bigelovii A. Gray – accepted – nodding ragwort
  Senecio bigelovii var. bigelovii A. Gray – accepted – nodding ragwort, Bigelow ragwort, Bigelow's ragwort
  Senecio bigelovii var. hallii A. Gray – accepted – Hall's ragwort
  Senecio bolanderi A. Gray – not accepted – Bolander's ragwort
  Senecio bolanderi var. bolanderi A. Gray – not accepted – Bolander's ragwort
  Senecio clarkianus A. Gray – accepted – Clark's ragwort
  Senecio crassulus A. Gray – accepted – thickleaf ragwort, thickleaf groundsel, meadow groundsel
  Senecio fendleri A. Gray – not accepted – Fendler's ragwort
  Senecio fremontii var. occidentalis A. Gray – accepted – dwarf mountain ragwort, western groundsel
  Senecio greenei A. Gray – not accepted – flame ragwort
  Senecio huachucanus A. Gray – not accepted
  Senecio lemmonii A. Gray – accepted – Lemmon's ragwort, Lemmon's groundsel
  Senecio lugens var. ochroleucus A. Gray – not accepted
  Senecio lyonii A. Gray – accepted – island senecio
  Senecio mohavensis A. Gray – accepted – Mojave ragwort, Mohave groundsel
  Senecio neomexicanus A. Gray – not accepted – New Mexico groundsel
  Senecio parryi A. Gray – accepted – mountain ragwort, Parry's groundsel
  Senecio rugelia A. Gray – not accepted
  Senecio serra var. integriusculus A. Gray – not accepted
  Senecio soldanella A. Gray – accepted – Colorado ragwort
  Senecio thurberi A. Gray – not accepted
  Serjania brachycarpa A. Gray – accepted – littlefruit slipplejack
  Seymeria scabra A. Gray – accepted – limpia blacksenna
  Sicydium lindheimeri A. Gray – not accepted
  Sicydium lindheimeri var. tenuisectum A. Gray – not accepted
  Sicyos cucumerinus A. Gray – accepted – Gray's bur cucumber
  Sicyos macrophyllus A. Gray – accepted – alpine bur cucumber, 'anunu
  Sicyosperma A. Gray – accepted – climbing arrowheads
  Sicyosperma gracile A. Gray – accepted – climbing arrowheads
  Sida cuneifolia A. Gray – not accepted
  Sida filipes A. Gray – not accepted
  Sida lepidota A. Gray – not accepted
  Sida lepidota var. sagittifolia A. Gray – not accepted
  Sida longipes A. Gray – accepted – stockflower fanpetals, long-stalked sida
  Sida neomexicana A. Gray – accepted – New Mexico fanpetals, New Mexico sida
  Sida physocalyx A. Gray – not accepted
  Sida tragiifolia A. Gray – accepted – tuberous sida, catnip noseburn, earleaf fanpetals, noseburn-leaf sida
  Sidalcea A. Gray – accepted – checkermallow, checkerbloom
  Sidalcea candida A. Gray – accepted – white checkermallow, white checkerbloom
  Sidalcea candida var. candida A. Gray – not accepted – white checkerbloom
  Sidalcea hirsuta A. Gray – accepted – hairy checkerbloom
  Sidalcea humilis A. Gray – not accepted
  Sidalcea neomexicana A. Gray – accepted – New Mexico checkerbloom, salt-spring checkerbloom, New Mexico checkermallow
  Sidalcea neomexicana ssp. neomexicana A. Gray – not accepted – salt spring checkerbloom
  Sidalcea pedata A. Gray – accepted – pedate checker-mallow, birdfoot checkerbloom, bird-foot checkerbloom
  Sidalcea vitifolia A. Gray – not accepted
  Silene lanceolata A. Gray – accepted – Kauai catchfly
  Silene struthioloides A. Gray – accepted – alpine catchfly
  Silene wrightii A. Gray – accepted – Wright's catchfly
  Silphium albiflorum A. Gray – accepted – white rosinweed
  Silphium asteriscus var. angustatum A. Gray – not accepted – starry rosinweed
  Silphium gracile A. Gray – not accepted – slender rosinweed
  Silphium trifoliatum var. latifolium A. Gray – not accepted – whorled rosinweed
  Simsia exaristata A. Gray – not accepted
  Simsia frutescens A. Gray – not accepted
  Simsia scaposa A. Gray – not accepted
  Sisymbrium auriculatum A. Gray – not accepted – Sisymbrium auriculatum, eared hedgemustard
  Sisymbrium incisum var. filipes A. Gray – not accepted
  Solanum torreyi A. Gray – not accepted
  Solanum xanthi A. Gray – not accepted
  Solanum xanti A. Gray – accepted – chaparral nightshade, purple nightshade
  Solanum xanti var. xanti A. Gray – not accepted – chaparral nightshade, xant nightshade
  Solidago arguta var. caroliniana A. Gray – accepted – Atlantic goldenrod
  Solidago bigelovii A. Gray – not accepted
  Solidago boothii var. ludoviciana A. Gray – not accepted
  Solidago boottii var. ludoviciana A. Gray – not accepted
  Solidago caesia var. paniculata A. Gray – not accepted
  Solidago californica var. nevadensis A. Gray – not accepted
  Solidago canadensis var. arizonica A. Gray – not accepted
  Solidago canadensis var. canescens A. Gray – not accepted
  Solidago chapmanii A. Gray – not accepted
  Solidago confinis A. Gray – accepted – Nevada goldenrod
  Solidago guiradonis A. Gray – accepted – Guirado goldenrod
  Solidago missouriensis var. extraria A. Gray – not accepted
  Solidago missouriensis var. montana A. Gray – not accepted
  Solidago multiradiata var. scopulorum A. Gray – not accepted – manyray goldenrod, Rocky Mountain goldenrod
  Solidago sparsiflora A. Gray – not accepted
  Solidago spathulata var. subcinerea A. Gray – not accepted
  Solidago ulmifolia var. microphylla A. Gray – not accepted – elmleaf goldenrod
  Solidago wrightii A. Gray – accepted – Wright's goldenrod
  Solidago wrightii var. wrightii A. Gray – not accepted – Wright's goldenrod
  Sophora stenophylla A. Gray – accepted – fringeleaf necklacepod, fringe-leaf necklacepod
  Sphaeralcea ambigua A. Gray – accepted – desert globemallow, apricot mallow
  Sphaeralcea ambigua ssp. ambigua A. Gray – not accepted – apricot globemallow
  Sphaeralcea ambigua var. ambigua A. Gray – accepted – apricot mallow
  Sphaeralcea angustifolia var. cuspidata A. Gray – not accepted
  Sphaeralcea fendleri A. Gray – accepted – thicket globe-mallow, Fendler's globemallow
  Sphaeralcea fendleri ssp. fendleri A. Gray – not accepted – Fendler's globemallow
  Sphaeralcea fendleri var. fendleri A. Gray – accepted
  Sphaeralcea hastulata A. Gray – accepted – spreading globemallow, spear globemallow
  Sphaeralcea hastuta A. Gray – not accepted
  Sphaeralcea incana var. dissecta A. Gray – not accepted
  Sphaeralcea incana var. oblongifolia A. Gray – not accepted
  Sphaeralcea lindheimeri A. Gray – accepted – woolly globemallow
  Sphaeralcea pedata var. angustiloba A. Gray – not accepted
  Sphaeralcea rusbyi A. Gray – accepted – Rusby's globemallow, cutleaf globemallow
  Sphaeralcea rusbyi ssp. rusbyi A. Gray – not accepted – Rusby's globemallow
  Sphaeralcea rusbyi var. rusbyi A. Gray – accepted
  Sphaeralcea wrightii A. Gray – accepted – Wright's globemallow
  Sphenosciadium A. Gray – accepted
  Sphenosciadium capitellatum A. Gray – accepted – button parsley, woollyhead parsnip
  Spigelia lindheimeri A. Gray – not accepted – prairie pinkroot
  Spiraea betulifolia var. rosea A. Gray – not accepted
  Sporobolus serotinus A. Gray – not accepted
  Spraguea umbellata var. caudicifera A. Gray – not accepted
  Stachys albens A. Gray – accepted – white hedgenettle, whitestem hedgenettle
  Stachys bigelovii A. Gray – accepted – rock hedgenettle
  Stachys hyssopifolia var. ambigua A. Gray – not accepted – hyssopleaf hedgenettle
  Stachys rothrockii A. Gray – accepted – Rothrock's hedge-nettle, Rothrock's hedgenettle
  Staphylea bolanderi A. Gray – accepted – Sierra bladdernut
  Stenandrium dulce var. floridanum A. Gray – not accepted
  Stenanthium occidentale A. Gray – not accepted – western featherbells
  Stenogyne angustifolia A. Gray – accepted – narrowleaf stenogyne
  Stenogyne angustifolia var. angustifolia A. Gray – not accepted
  Stenogyne calaminthoides A. Gray – accepted – bog stenogyne
  Stenogyne crenata A. Gray – not accepted
  Stenogyne diffusa A. Gray – not accepted
  Stenogyne rotundifolia A. Gray – accepted – pua`ainaka
  Stephanomeria cichoriacea A. Gray – accepted – chicoryleaf wirelettuce
  Stephanomeria lactucina A. Gray – accepted – lettuce wirelettuce, creeping wirelettuce
  Stephanomeria parryi A. Gray – accepted – Parry's wirelettuce, Parry's wire lettuce
  Stephanomeria schottii A. Gray – not accepted – Schott's wirelettuce, Schott's wire lettuce
  Stephanomeria thurberi A. Gray – accepted – Thurber's wirelettuce, Thurber's wire lettuce
  Stephanomeria wrightii A. Gray – not accepted – Wright's wirelettuce
  Stevia plummerae A. Gray – accepted – Plummer's candyleaf
  Stevia plummerae var. alba A. Gray – not accepted – Plummer's candyleaf
  Stevia plummerae var. plummerae A. Gray – accepted – Plummer's candyleaf
  Stevia stenophylla A. Gray – not accepted
  Streptanthus bracteatus A. Gray – accepted – bracted jewelflower, bracted twistflower
  Streptanthus breweri A. Gray – accepted – Brewer's jewelflower
  Streptanthus breweri var. breweri A. Gray – not accepted – Brewer's jewelflower, jewelflower
  Streptanthus hispidus A. Gray – accepted – Mount Diablo jewelflower
  Streptanthus micranthus A. Gray – not accepted
  Streptanthus petiolaris A. Gray – accepted – Brazos rockcress
  Streptanthus platycarpus A. Gray – accepted – broadpod jewelflower
  Streptanthus polygaloides A. Gray – accepted – milkwort jewelflower
  Stylocline micropoides A. Gray – accepted – woollyhead neststraw, desert neststraw, woolly neststraw
  Suckleya A. Gray – accepted
  Suckleyi A. Gray – not accepted
  Suksdorfia A. Gray – accepted
  Suksdorfia violacea A. Gray – accepted – violet suksdorfia
  Symphoricarpos longiflorus A. Gray – accepted – longleaf snowberry, desert snowberry
  Symphoricarpos mollis var. acutus A. Gray – not accepted
  Symphoricarpos oreophilus A. Gray – accepted – whortleleaf snowberry, mountain snowberry
  Symphoricarpos oreophilus var. oreophilus A. Gray – accepted – mountain snowberry
  Symphoricarpos rotundifolius A. Gray – accepted – coralberry, roundleaf snowberry
  Symphoricarpos rotundifolius var. rotundifolius A. Gray – accepted – roundleaf snowberry
  Synthlipsis A. Gray – accepted
  Synthlipsis greggii A. Gray – accepted – Gregg's keelpod
  Synthyris alpina A. Gray – accepted – alpine kittentails
  Synthyris pinnatifida var. laciniata A. Gray – not accepted
  Synthyris reniformis var. cordata A. Gray – not accepted – snowqueen
  Syntrichopappus A. Gray – accepted – Fremont's-gold, Fremont's gold
  Syntrichopappus fremontii A. Gray – accepted – yellowray Fremont's-gold, yellow-ray Fremont's-gold, Fremont's gold
  Tagetes lemmonii A. Gray – accepted – Lemmon's marigold
  Tagetes palmeri A. Gray – not accepted
  Talinopsis A. Gray – accepted
  Talinopsis frutescens A. Gray – accepted – arroyo fameflower
  Talinum pygmaeum A. Gray – not accepted
  Tauschia texana A. Gray – accepted – Texas umbrellawort
  Tephrosia leiocarpa A. Gray – accepted – smoothpod hoarypea, smooth pod tephrosia
  Tephrosia lieocarpa A. Gray – not accepted
  Tephrosia lindheimeri A. Gray – accepted – Lindheimer's hoarypea, goat's rue
  Tephrosia tenella A. Gray – accepted – red hoarypea, red hoary-pea
  Tetraclea A. Gray – accepted
  Tetraclea coulteri A. Gray – accepted – Coulter's wrinklefruit
  Tetraclea coulteri var. coulteri A. Gray – not accepted – Coulter's wrinklefruit
  Tetradymia comosa A. Gray – accepted – hairy horsebrush
  Tetraplasandra A. Gray – not accepted
  Tetraplasandra hawaiensis A. Gray – not accepted – Hawai'i `ohe
  Tetraplasandra hawaiiensis var. hawaiiensis A. Gray – not accepted
  Teucrium canadense var. angustatum A. Gray – not accepted
  Teucrium occidentale A. Gray – not accepted
  Thalictrum occidentale A. Gray – accepted – western meadowrue, western meadow-rue
  Thalictrum occidentale var. occidentale A. Gray – not accepted – western meadowrue, western meadow-rue
  Thaspium montanum A. Gray – not accepted
  Thelesperma ambiguum A. Gray – accepted – Colorado greenthread
  Thelesperma longipes A. Gray – accepted – longstalk greenthread, long-stalk greenthread, rayless greenthread
  Thelesperma simplicifolium A. Gray – accepted – slender greenthread, Edwards Plateau greenthread
  Thelesperma subnudum A. Gray – accepted – Navajo tea, hairy greenthread, low greenthread, Navajo-tea, sand fringedpod
  Thelesperma subnudum var. subnudum A. Gray – not accepted – Navajo tea
  Thelypodium wrightii A. Gray – accepted – Wright's stanleyella, Wright's thelypody
  Thelypodium wrightii ssp. wrightii A. Gray – not accepted – Wright's thelypody
  Thlaspi fendleri A. Gray – not accepted
  Thurberia thespesioides A. Gray – not accepted
  Thymophylla polychaeta A. Gray – not accepted
  Tithonia thurberi A. Gray – accepted – Arizona sunflowerweed, Arizona sunflower weed
  Tonella floribunda A. Gray – accepted – manyflower tonella
  Townsendia arizonica A. Gray – not accepted
  Townsendia eximia A. Gray – accepted – tall Townsend daisy, tall townsendia
  Townsendia fendleri A. Gray – accepted – Fendler's Townsend daisy
  Townsendia glabella A. Gray – accepted – Gray's Townsend daisy
  Townsendia sericea var. leptotes A. Gray – not accepted
  Trichocoronis A. Gray – accepted – bugheal
  Trichocoronis rivularis A. Gray – not accepted – Rio Grande bugheal
  Trichomanes petersii A. Gray – not accepted – dwarf bristle fern
  Trichoptilium A. Gray – accepted – trichoptilium
  Trichostema arizonicum A. Gray – accepted – Arizona bluecurls
  Trichostema laxum A. Gray – accepted – turpentine weed
  Trichostema micranthum A. Gray – accepted – small-flower bluecurls, smallflower bluecurls
  Trifolium andersonii A. Gray – accepted – fiveleaf clover
  Trifolium andersonii ssp. andersonii A. Gray – accepted – fiveleaf clover, Anderson's clover
  Trifolium barbigerum var. andrewsii A. Gray – accepted – Andrews' clover
  Trifolium bifidum A. Gray – accepted – notchleaf clover
  Trifolium bolanderi A. Gray – accepted – parasol clover
  Trifolium longipes var. pygmaeum A. Gray – not accepted
  Trifolium monanthum A. Gray – accepted – mountain carpet clover, carpet clover
  Trifolium monanthum ssp. monanthum A. Gray – accepted – mountain carpet clover
  Trifolium parryi A. Gray – accepted – Parry's clover, Parry clover
  Trifolium parryi ssp. parryi A. Gray – accepted – Parry's clover
  Trifolium subcaulescens A. Gray – not accepted
  Trollius laxus var. albiflorus A. Gray – not accepted
  Utricularia occidentalis A. Gray – not accepted
  Utricularia vulgaris var. americana A. Gray – not accepted
  Vaccinium caespitosum var. arbuscula A. Gray – not accepted
  Vaccinium cespitosum var. arbuscula A. Gray – not accepted
  Vaccinium constablaei A. Gray – not accepted
  Vaccinium corymbosum var. atrococcum A. Gray – not accepted
  Vaccinium corymbosum var. glabrum A. Gray – not accepted
  Vaccinium myrsinites var. glaucum A. Gray – not accepted
  Vaccinium occidentale A. Gray – not accepted
  Vaccinium occidentalis A. Gray – not accepted
  Vaccinium oxycoccos var. intermedium A. Gray – not accepted
  Vaccinium parviflorum A. Gray – not accepted
  Valeriana arizonica A. Gray – accepted – Arizona tobaccoroot, Arizona valerian
  Varilla A. Gray – accepted – varilla
  Varilla texana A. Gray – accepted – Texas varilla
  Veratrum eschscholtzii A. Gray – not accepted
  Veratrum fimbriatum A. Gray – accepted – fringed false hellebore
  Verbena wrightii A. Gray – not accepted
  Verbesina dissita A. Gray – accepted – bigleaf crownbeard, big-leaved crown-beard, big-leaved crownbeard
  Verbesina podocephala A. Gray – not accepted
  Verbesina warei A. Gray – not accepted
  Veronica cusickii A. Gray – accepted – Cusick's speedwell
  Vesicaria lescurii A. Gray – not accepted
  Viburnum nudum var. grandifolium A. Gray – not accepted
  Vigna sandwicensis A. Gray – not accepted
  Viguiera cordifolia A. Gray – accepted – heartleaf goldeneye, mountain goldeneye
  Viguiera deltoidea A. Gray – accepted – triangle goldeneye
  Viguiera deltoidea var. deltoidea A. Gray – not accepted – triangle goldeneye
  Viguiera laciniata A. Gray – not accepted – torhleaf goldeneye
  Vilfa heterolepis A. Gray – not accepted
  Viola blanda var. palustriformis A. Gray – not accepted – sweet white violet
  Viola canadensis var. scopulorum A. Gray – accepted – Canadian white violet
  Viola hallii A. Gray – accepted – Oregon violet
  Viola howellii A. Gray – accepted – Howell's violet
  Viola kauaensis A. Gray – accepted – pohe hiwa
  Viola kauaensis var. kauaensis A. Gray – accepted – pohe hiwa
  Viola primulifolia var. occidentalis A. Gray – accepted – bog white violet
  Viola renifolia A. Gray – accepted – northern white violet, white violet
  Viola renifolia var. renifolia A. Gray – not accepted – kidneyleaf white violet
  Vittadinia remyi A. Gray – not accepted
  Waltheria detonsa A. Gray – accepted
  Waltheria pyrolaefolia A. Gray – not accepted
  Waltheria pyrolifolia A. Gray – not accepted
  Weinmannia affinis A. Gray – accepted
  Whitneya A. Gray – not accepted – whitneya
  Whitneya dealbata A. Gray – not accepted – mock leopardbane
  Wikstroemia elongata A. Gray – not accepted
  Wikstroemia phillyreifolia A. Gray – accepted – Hawai'i false ohelo
  Wikstroemia phillyreifolia var. rigida A. Gray – not accepted
  Wikstroemia uva-ursi A. Gray – accepted – hillside false ohelo
  Wikstroemia uva-ursi var. uva-ursi A. Gray – accepted – hillside false ohelo
  Wilkesia A. Gray – accepted – iliau
  Wilkesia gymnoxiphium A. Gray – accepted – iliau
  Wislizenia palmeri A. Gray – accepted – Palmer's wislizenia
  Wyethia arizonica A. Gray – accepted – Arizona mule-ears, Arizona mulesears
  Wyethia glabra A. Gray – accepted – Coast Range mule-ears
  Wyethia lingicaulis A. Gray – not accepted
  Wyethia longicaulis A. Gray – accepted – Humboldt mule-ears
  Wyethia mollis A. Gray – accepted – woolly mule-ears, wooly wyethia
  Ximenesia encelioides var. nana A. Gray – not accepted
  Xylosma buxifolia A. Gray – accepted – mucha-gente
  Xylosma schaefferioides A. Gray – accepted – white logwood
  Zanthoxylum kauaense A. Gray – accepted – Kauai pricklyash
  Zexmenia brevifolia A. Gray – not accepted
  Zigadenus leimanthoides A. Gray – not accepted – pinebarren deathcamas, pine barren deathcamas
  Zinnia anomala A. Gray – accepted – shortray zinnia
  Zinnia palmeri A. Gray – accepted – Palmer's zinnia
  Zinnia pumila A. Gray – not accepted
   

A gray bar