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Taxon author: Hitchc.

ITIS records citing taxon author "Hitchc."
 
 Kingdom Animalia
  Capnia quadrituberosa Hitchcock, 1958 -- valid
  Cisticola juncidis leanyeri Givens & Hitchcock, 1953 -- valid
  Leuctra laura Hitchcock, 1969 -- valid
  Malenka marionae (Hitchcock, 1958) -- valid
  Malurus alboscapulatus kutubu Schodde & Hitchcock, 1968 -- valid
  Paraleuctra divisa (Hitchcock, 1958) -- valid
 
 Kingdom Plantae
  Abronia umbellata var. acutalata (Standl.) C.L. Hitchc. -- accepted -- pink sand verbena
  Acerates floridana (Lam.) Hitchc. -- not accepted
  Achimenes pulchella (L'Hér.) Hitchc. -- not accepted
  Achnatherum constrictum (Hitchc.) Valdés-Reyna & Barkworth -- accepted
  Achnatherum swallenii (C.L. Hitchc. & Spellenb.) Barkworth -- accepted -- Swallen's needlegrass
  Aconitum columbianum var. howellii (A. Nelson & J.F. Macbr.) C.L. Hitchc. -- not accepted
  Agropyron breviaristatum Hitchc. -- not accepted
  Agropyron caninum ssp. majus (Vasey) C.L. Hitchc. -- not accepted
  Agropyron dasystachyum var. sericeum (Hitchc.) B. Boivin -- not accepted
  Agropyron laeve (Scribn. & J.G. Sm.) Hitchc. -- not accepted
  Agropyron pauciflorum (Schwein.) Hitchc. ex Silveus -- not accepted
  Agropyron pringlei (Scribn. & J.G. Sm.) Hitchc. -- not accepted
  Agropyron saundersii (Vasey) Hitchc. -- not accepted
  Agropyron sericeum Hitchc. -- not accepted
  Agropyron subsecundum (Link) Hitchc. -- not accepted
  Agropyron subsecundum var. andinum (Scribn. & J.G. Sm.) Hitchc. -- not accepted
  Agropyron subsecundum var. subsecundum (Link) Hitchc. -- not accepted
  Agropyron vulpinum (Rydb.) Hitchc. -- not accepted
  Agrostis ampla Hitchc. -- not accepted -- bigspike bentgrass
  Agrostis blasdalei Hitchc. -- accepted -- Blasdale bentgrass
  Agrostis blasdalei var. blasdalei Hitchc. -- not accepted -- Blasdale bentgrass
  Agrostis breviculmis Hitchc. -- accepted
  Agrostis capillaris var. aristulata Hitchc. -- not accepted
  Agrostis exarata ssp. minor (Hook.) C.L. Hitchc. -- not accepted
  Agrostis exarata var. microphylla (Steud.) Hitchc. -- not accepted
  Agrostis exarata var. monolepis (Torr.) Hitchc. -- not accepted -- monolepis bentgrass
  Agrostis haenkeana Hitchc. -- not accepted
  Agrostis hallii var. pringlei (Scribn.) Hitchc. -- not accepted -- Pringle's bentgrass
  Agrostis hendersonii Hitchc. -- accepted -- Henderson's bentgrass
  Agrostis hiemalis var. geminata (Trin.) Hitchc. -- not accepted
  Agrostis hiemalis var. subrepens Hitchc. -- not accepted
  Agrostis hyemalis var. geminata (Trin.) Hitchc. -- not accepted
  Agrostis hyemalis var. subrepens Hitchc. -- not accepted
  Agrostis lepida Hitchc. -- not accepted -- Sequoia bentgrass
  Agrostis liebmannii (E. Fourn.) Hitchc. -- accepted
  Agrostis longiligula Hitchc. -- not accepted -- longtongue bentgrass
  Agrostis longiligula var. longiligula Hitchc. -- not accepted -- longtongue bentgrass
  Agrostis melaleuca (Trin.) Hitchc. -- not accepted
  Agrostis microphylla var. hendersonii (Hitchc.) Beetle -- not accepted
  Agrostis microphyllus var. hendersoni (Hitchc.) Beetle -- not accepted
  Agrostis pallens var. foliosa Hitchc. -- not accepted
  Agrostis perennans var. elata (Pursh) Hitchc. -- not accepted
  Agrostis subpatens Hitchc. -- accepted
  Agrostis subrepens (Hitchc.) Hitchc. -- accepted
  Agrostis thurberiana Hitchc. -- not accepted -- Thurber's bentgrass
  Aira conferta (Pilg.) Hitchc. -- not accepted
  Alloteropsis amphistemon (C. Wright) Hitchc. -- not accepted
  Alloteropsis dura (Griseb.) Hitchc. -- not accepted
  Alnus incana var. occidentalis (Dippel) C.L. Hitchc. -- not accepted
  Amelanchier alnifolia var. cusickii (Fernald) C.L. Hitchc. -- not accepted -- Cusick's serviceberry
  Amelanchier alnifolia var. humptulipensis (G.N. Jones) C.L. Hitchc. -- not accepted -- Saskatoon serviceberry
  Amelanchier alnifolia var. semiintegrifolia (Hook.) C.L. Hitchc. -- accepted -- Pacific serviceberry, Saskatoon serviceberry
  Amphicarpum muehlenbergianum (Schult.) Hitchc. -- not accepted -- Muhlenberg maidencane, perennial goobergrass
  Amphicarpum muhlenbergianum (Schult.) Hitchc. -- accepted
  Anatherostipa rosea (Hitchc.) Peńailillo -- accepted
  Anatherum virginicum subvar. nashianum (Hitchc.) Roberty -- not accepted
  Anatherum virginicum subvar. urbanianum (Hitchc.) Roberty -- not accepted
  Anatherum zizanioides (L.) Hitchc. & Chase -- not accepted
  Andropogon aequatoriensis Hitchc. -- accepted
  Andropogon altus Hitchc. -- not accepted
  Andropogon divergens (Hack.) Andersson ex Hitchc. -- not accepted
  Andropogon exaristatus (Nash) Hitchc. -- not accepted
  Andropogon gaumeri (Nash) Hitchc. -- not accepted
  Andropogon gracilis var. firmior Hitchc. -- accepted
  Andropogon mexicanus Hitchc. -- not accepted
  Andropogon muelleri (Nash) Hitchc. -- not accepted
  Andropogon multinervosus (Nash) Hitchc. & Chase -- not accepted
  Andropogon nashianus Hitchc. -- not accepted
  Andropogon parvifolius Hitchc. -- not accepted
  Andropogon reedii Hitchc. & Ekman -- not accepted
  Andropogon saccharoides ssp. parvispiculus Hitchc. -- not accepted
  Andropogon saccharoides var. parvispiculus (Hitchc.) Standl. -- not accepted
  Andropogon salzmannii (Trin. ex Steud.) Hitchc. -- not accepted
  Andropogon scoparius var. littoralis (Nash) Hitchc. -- not accepted
  Andropogon stolonifer (Nash) Hitchc. -- not accepted
  Andropogon urbanianus Hitchc. -- accepted
  Andropogon virginicus var. glaucopsis (Elliott) Hitchc. -- not accepted
  Andropogon virginicus var. hirsutior (Hack.) Hitchc. -- not accepted
  Anemone drummondii var. lithophila (Rydb.) C.L. Hitchc. -- accepted -- Little Belt Mountain thimbleweed
  Anemone multifida var. hirsuta C.L. Hitchc. -- not accepted -- Pacific anemone
  Anemone multifida var. tetonensis (Porter ex Britton) C.L. Hitchc. -- accepted -- Pacific anemone
  Anemone oregana var. felix (M. Peck) C.L. Hitchc. -- accepted -- bog anemone, Felix anemone
  Arberella costaricensis (Hitchc.) Soderstr. & C.E. Calderón -- accepted
  Arenaria kingii var. uintahensis (A. Nelson) C.L. Hitchc. -- not accepted
  Arenaria nuttallii var. fragilis (Maguire & A.H. Holmgren) C.L. Hitchc. -- not accepted
  Arenaria stricta var. puberulenta (M. Peck) C.L. Hitchc. -- not accepted
  Aristida berlandieri (Trin. & Rupr.) Hitchc. -- not accepted
  Aristida brittonorum Hitchc. -- accepted
  Aristida calcicola Hitchc. & Ekman -- accepted
  Aristida chaseae Hitchc. -- accepted -- Chase's threeawn
  Aristida curtifolia Hitchc. -- accepted
  Aristida eggersii Hitchc. -- not accepted
  Aristida erecta Hitchc. -- accepted
  Aristida fournieriana Hitchc. -- not accepted
  Aristida fragilis Hitchc. & Ekman -- accepted
  Aristida glabrata (Vasey) Hitchc. -- not accepted
  Aristida hintonii Hitchc. -- accepted
  Aristida laevigata Hitchc. & Ekman -- accepted
  Aristida lanuginosa Scribn. ex Hitchc. -- not accepted
  Aristida longiseta ssp. rariflora Hitchc. -- not accepted
  Aristida longiseta var. rariflora (Hitchc.) Hitchc. -- not accepted
  Aristida neglecta León ex Hitchc. -- accepted
  Aristida parishii Hitchc. -- not accepted
  Aristida peninsularis Hitchc. -- not accepted
  Aristida purpurascens var. tenuispica (Hitchc.) Allred -- accepted -- arrowfeather threeawn
  Aristida purpurea var. parishii (Hitchc.) Allred -- accepted -- Parish threeawn, Parish's threeawn
  Aristida purpusiana Hitchc. -- accepted
  Aristida rariflora (Hitchc.) Henrard -- not accepted
  Aristida rosei Hitchc. -- accepted
  Aristida scribneriana Hitchc. -- accepted
  Aristida tenuifolia Hitchc. -- accepted
  Aristida tenuispica Hitchc. -- not accepted
  Aristida ternipes var. divergens (Vasey) Hitchc. -- not accepted
  Aristida ternipes var. minor (Vasey) Hitchc. -- accepted -- spidergrass
  Aristida vaginata Hitchc. -- accepted
  Aristida wrightii var. parishii (Hitchc.) Gould -- not accepted
  Arrhenatherum bulbosum var. variegatum Hitchc. -- not accepted
  Arthrostylidium ekmanii Hitchc. -- accepted
  Arthrostylidium haitiense (Pilg.) Hitchc. & Chase -- accepted
  Arthrostylidium maxonii Hitchc. -- not accepted
  Arthrostylidium reflexum Hitchc. & Ekman -- accepted
  Arundinaria standleyi Hitchc. -- not accepted
  Arundinaria viscosa Hitchc. -- not accepted
  Arundinella berteroniana (Schult.) Hitchc. & Chase -- accepted
  Arundinella confinis (Schult.) Hitchc. & Chase -- not accepted -- rabo de gato
  Aspris capillaris (Mert. & W.D.J. Koch) Hitchc. -- not accepted
  Astragalus howellii var. aberrans (M.E. Jones) C.L. Hitchc. -- not accepted
  Astragalus reventus var. oxytropidoides (M.E. Jones) C.L. Hitchc. -- not accepted
  Astragalus reventus var. sheldonii (Rydb.) C.L. Hitchc. -- not accepted
  Astragalus robbinsii var. alpiniformis (Rydb.) Barneby ex C.L. Hitchc. -- accepted -- Robbins milk-vetch, Robbins' milkvetch
  Astragalus spaldingii var. tyghensis (M. Peck) C.L. Hitchc. -- not accepted
  Atriplex canescens var. aptera (A. Nelson) C.L. Hitchc. -- not accepted
  Atriplex oatula var. zosterifolia (Hook.) C.L. Hitchc. -- not accepted
  Atriplex patula var. zosterifolia (Hook.) C.L. Hitchc. -- not accepted
  Aulonemia viscosa (Hitchc.) McClure -- accepted
  Axonopus anceps (Mez) Hitchc. -- accepted
  Axonopus appendiculatus (J. Presl) Hitchc. & Chase -- not accepted
  Axonopus attenuatus (J. Presl) Hitchc. -- not accepted
  Axonopus barbiger (Kunth) Hitchc. -- not accepted
  Axonopus barbiger var. barbiger (Kunth) Hitchc. -- not accepted
  Axonopus blakei Hitchc. -- not accepted
  Axonopus elegantulus (J. Presl) Hitchc. -- accepted
  Axonopus equitans Hitchc. & Chase -- accepted
  Axonopus furcatus (Flüggé) Hitchc. -- accepted -- big carpetgrass
  Axonopus herzogii (Hack.) Hitchc. -- accepted
  Axonopus iridaceus (Mez) Hitchc. & Chase ex Rojas -- not accepted
  Axonopus leptostachyus (Flüggé) Hitchc. -- accepted
  Axonopus macrostachyus Hitchc. & Chase -- not accepted
  Axonopus mathewsii (Mez) Hitchc. -- accepted
  Axonopus micay Fluegge ex Hitchc. ex Perez Arbelaez -- not accepted
  Axonopus pellitus (Nees ex Trin.) Hitchc. & Chase -- accepted
  Axonopus scoparius (Flüggé) Hitchc. -- not accepted -- carpetgrass
  Bambusa aculeata (Rupr. ex E. Fourn.) Hitchc. -- not accepted
  Betula glandulosa var. hallii (Howell) C.L. Hitchc. -- not accepted
  Betula occidentalis var. inopina (Jeps.) C.L. Hitchc. -- not accepted
  Blepharidachne benthamiana (Hack. ex Kuntze) Hitchc. -- accepted
  Bothriochloa alta (Hitchc.) Henrard -- accepted -- tall beardgrass
  Bothriochloa alta (Hitchc.) Cabrera -- not accepted
  Bothriochloa saccharoides ssp. parvispicula (Hitchc.) Davidse -- not accepted
  Bothriochloa saccharoides var. parvispicula (Hitchc.) Tovar -- accepted
  Botrychium simplex E. Hitchc. -- accepted -- botryche simple, least moonwort, little grapefern
  Botrychium simplex ssp. simplex E. Hitchc. -- not accepted
  Botrychium simplex var. simplex E. Hitchc. -- not accepted -- little grapefern
  Bouteloua americana (L.) Hitchc. -- not accepted
  Bouteloua gracilis var. stricta (Vasey) Hitchc. -- not accepted
  Bouteloua juncea (Desv. ex P. Beauv.) Hitchc. -- accepted -- lamilla
  Bouteloua rigidiseta (Steud.) Hitchc. -- accepted -- Texas grama
  Brachiaria meziana Hitchc. -- not accepted
  Brachiaria plantaginea (Link) Hitchc. -- not accepted -- plantain signalgrass
  Brachiaria subquadripara (Trin.) Hitchc. -- not accepted -- tropical signalgrass
  Bromelica striata (Hitchc.) Farw. -- not accepted
  Bromopsis inermis var. pumpelliana (Scribn.) C.L. Hitchc. -- not accepted
  Bromus anomalus var. lanatipes (Shear) Hitchc. -- not accepted
  Bromus carinatus var. marginatus Hitchc. ex Scoggan -- not accepted
  Bromus carinatus var. maritimus (Piper) C.L. Hitchc. -- not accepted
  Bromus catharticus var. striatus (Hitchc.) Pinto -- not accepted
  Bromus grandis (Shear) Hitchc. -- accepted -- tall brome
  Bromus hallii (Hitchc.) Saarela & P.M. Peterson -- accepted
  Bromus incanus (Shear) Hitchc. -- not accepted
  Bromus inermis ssp. pumpellianus var. pumpellianus (Scribn.) C.L. Hitchc. -- not accepted -- Pumpelly's brome
  Bromus inermis var. pumpellianus C.L. Hitchc. -- not accepted -- Pumpelly's brome
  Bromus inermis var. tweedyi (Scribn. ex Beal) C.L. Hitchc. -- not accepted
  Bromus laeviglumis (Scribn. ex Shear) Hitchc. -- not accepted
  Bromus latiglumis (Scribn. ex Shear) Hitchc. -- accepted -- broad-glumed brome, early-leaf brome, earlyleaf brome
  Bromus latiglumis f. latiglumis (Scribn. ex Shear) Hitchc. -- accepted
  Bromus maritimus (Piper) Hitchc. -- accepted -- seaside brome
  Bromus orcuttianus var. hallii Hitchc. -- not accepted -- Hall's brome
  Bromus striatus Hitchc. -- accepted
  Bromus texensis (Shear) Hitchc. -- accepted -- Texas brome
  Bromus villosissimus Hitchc. -- accepted
  Calamagrostis antoniana (Griseb.) Steud. ex Hitchc. -- not accepted
  Calamagrostis cainii Hitchc. -- accepted -- Cain's reedgrass
  Calamagrostis canadensis var. imberbis (Stebbins) C.L. Hitchc. -- accepted -- bluejoint
  Calamagrostis canadensis var. lactea (Suksd. ex Beal) C.L. Hitchc. -- not accepted
  Calamagrostis canadensis var. scabra (J. Presl) Hitchc. -- not accepted
  Calamagrostis cryptolopha (Wedd.) Hitchc. -- accepted
  Calamagrostis curta (Wedd.) Hitchc. -- accepted
  Calamagrostis erectifolia Hitchc. -- accepted
  Calamagrostis expansa (Munro ex Hbd.) Hitchc. -- accepted -- Maui reedgrass
  Calamagrostis glacialis (Wedd.) Hitchc. -- accepted
  Calamagrostis guatemalensis Hitchc. -- accepted
  Calamagrostis haenkeana Hitchc. -- not accepted
  Calamagrostis hillebrandii (Munro ex Hillebr.) Hitchc. -- accepted -- Hillebrand's reedgrass, Hillegrand's reedgrass
  Calamagrostis leiophylla (Wedd.) Hitchc. -- accepted
  Calamagrostis ligulata (Kunth) Hitchc. -- accepted
  Calamagrostis orbignyana (Wedd.) Hitchc. -- not accepted
  Calamagrostis pickeringii var. lacustris (Kearney) Hitchc. -- not accepted
  Calamagrostis preslii (Kunth) Hitchc. -- accepted
  Calamagrostis schiedeana (Rupr. ex E. Fourn.) Hitchc. -- not accepted
  Calamagrostis stipitata Hitchc. -- not accepted
  Calamagrostis violacea (Wedd.) Hitchc. -- not accepted
  Caltha biflora var. rotundifolia (Huth) C.L. Hitchc. -- not accepted
  Caltha leptosepala ssp. leptosepala var. sulfurea C.L. Hitchc. -- not accepted -- sulphur marsh marigold
  Caltha leptosepala var. sulfurea C.L. Hitchc. -- not accepted -- sulphur marsh marigold
  Camassia leichtlinii var. suksdorfii (Greenm.) C.L. Hitchc. -- not accepted
  Camassia quamash var. azurea (A. Heller) C.L. Hitchc. -- not accepted
  Camassia quamash var. breviflora (Gould) C.L. Hitchc. -- not accepted
  Camassia quamash var. intermedia (Gould) C.L. Hitchc. -- not accepted
  Camassia quamash var. utahensis (Gould) C.L. Hitchc. -- not accepted
  Campulosus floridanus Hitchc. -- not accepted
  Campulosus plumosus Hitchc. -- not accepted
  Capriola dactylon (L.) Hitchc. -- not accepted
  Capriola dactylon var. maritima (Kunth) Hitchc. -- not accepted
  Cardamine breweri var. leibergii (Holz.) C.L. Hitchc. -- not accepted -- Leiberg's bittercress
  Cardamine integrifolia var. sinuata (Greene) C.L. Hitchc. -- not accepted
  Cardamine pulcherrima var. tenella (Pursh) C.L. Hitchc. -- not accepted
  Cardamine rupicola (O.E. Schulz) C.L. Hitchc. -- accepted -- cliff bittercress
  Cassiope mertensiana var. gracilis (Piper) C.L. Hitchc. -- accepted -- western moss heather
  Cassiope tetragona var. saximontana (Small) C.L. Hitchc. -- accepted -- white arctic mountain heather
  Catabrosa burkartii Hitchc. -- not accepted
  Cenchrus echinatus var. hillebrandianus (Hitchc.) F. Br. -- not accepted
  Cenchrus ekmanianus Hitchc. -- not accepted
  Cenchrus hillebrandianus Hitchc. -- not accepted
  Cenchrus humilis Hitchc. -- not accepted
  Cenchrus microcephalus Nash ex Hitchc. & Chase -- not accepted
  Chaboissaea subbiflora (Hitchc.) Reeder & C. Reeder -- not accepted
  Chaetium cubanum (C. Wright) Hitchc. -- accepted
  Chaetochloa argentina (R.A.W. Herrm.) Hitchc. -- not accepted
  Chaetochloa aurea (Hochst. ex A. Braun) Hitchc. -- not accepted
  Chaetochloa barbata (Lam.) Hitchc. & Chase -- not accepted
  Chaetochloa barbinodis (R.A.W. Herrm.) Hitchc. -- not accepted
  Chaetochloa cernua (Kunth) Hitchc. -- not accepted
  Chaetochloa effusa (E. Fourn.) Hitchc. -- not accepted
  Chaetochloa impressa (Nees) Hitchc. & Chase -- not accepted
  Chaetochloa lachnea (Nees) Hitchc. -- not accepted
  Chaetochloa membranifolia (R.A.W. Herrm.) Hitchc. -- not accepted
  Chaetochloa oblongata (Griseb.) Hitchc. -- not accepted
  Chaetochloa palmifolia Hitchc. & Chase -- not accepted
  Chaetochloa poiretiana (Schult.) Hitchc. -- not accepted
  Chaetochloa rariflora (J.C. Mikan ex Trin.) Hitchc. & Chase -- not accepted
  Chaetochloa salzmanniana Hitchc. -- not accepted
  Chaetochloa scheelei (Steud.) Hitchc. -- not accepted
  Chaetochloa sulcata (Aubl.) Hitchc. -- not accepted
  Chaetochloa tenacissima (Schrad. ex Schult.) Hitchc. & Chase -- not accepted
  Chaetochloa tenax (Rich.) Hitchc. -- not accepted
  Chaetochloa trichorhachis (Hack.) Hitchc. -- not accepted
  Chaetochloa vulpiseta (Lam.) Hitchc. & Chase -- not accepted
  Chamaerhodos erecta var. parviflora (Nutt.) C.L. Hitchc. -- not accepted
  Chamaesyce blodgettii (Engelm. ex Hitchc.) Small -- not accepted -- limestone sandmat
  Chimaerochloa archboldii (Hitchc.) Pirie & H. P. Linder -- accepted
  Chiococca alba (L.) Hitchc. -- accepted -- West Indian milkberry
  Chionochloa archboldii (Hitchc.) Conert -- not accepted
  Chloris arenaria Hitchc. & Ekman -- accepted
  Chloris chloridea (J. Presl) Hitchc. -- not accepted
  Chloris cubensis Hitchc. & Ekman -- not accepted -- Cuban windmill grass
  Chloris ekmanii Hitchc. -- accepted
  Chloris leptantha Hitchc. ex Urb. -- not accepted
  Chloris luetzelburgii Hitchc. -- not accepted
  Chloris rupestris (Ridl.) Hitchc. -- not accepted
  Chloris sagraeana ssp. cubensis (Hitchc. & Ekman) Catasús -- accepted
  Chloris suringarii Hitchc. -- accepted
  Chorizanthe brevicornu var. spathulata (Small ex Rydb.) C.L. Hitchc. -- accepted -- brittle spineflower
  Chusquea delicatula Hitchc. -- accepted
  Chusquea heydei Hitchc. -- not accepted
  Chusquea lanceolata Hitchc. -- accepted
  Chusquea subtessellata Hitchc. -- accepted
  Clarkia amoena var. caurina (Abrams ex Piper) C.L. Hitchc. -- not accepted
  Clarkia amoena var. lindleyi (Douglas) C.L. Hitchc. -- not accepted
  Clarkia amoena var. pacifica (M. Peck) C.L. Hitchc. -- not accepted
  Clarkia gracilis ssp. sonomensis (C.L. Hitchc.) F.H. Lewis & M.E. Lewis -- accepted -- Sonoma clarkia
  Claytonia lanceolata var. chrysantha (Greene) C.L. Hitchc. -- not accepted -- lanceleaf springbeauty
  Claytonia lanceolata var. flava (A. Nelson) C.L. Hitchc. -- not accepted -- lanceleaf springbeauty
  Claytonia lanceolata var. multiscapa (Rydb.) C.L. Hitchc. -- not accepted -- lanceleaf springbeauty
  Claytonia megarhiza var. bellidiflora (Rydb.) C.L. Hitchc. -- not accepted
  Claytonia megarhiza var. bellidifolia (Rydb.) C.L. Hitchc. -- not accepted -- alpine springbeauty
  Claytonia megarhiza var. nivalis (English) C.L. Hitchc. -- not accepted -- alpine springbeauty
  Clematis columbiana var. dissecta C.L. Hitchc. -- not accepted
  Clematis occidentalis var. dissecta (C.L. Hitchc.) J.S. Pringle -- accepted -- western blue virginsbower
  Coleataenia anceps ssp. rhizomata (Hitchc. & Chase) Soreng -- accepted
  Coleataenia petersonii (Hitchc. & Ekman) Soreng -- accepted
  Comandra umbellata var. californica (Eastw. ex Rydb.) C.L. Hitchc. -- not accepted
  Cornus stolonifera var. occidentalis (Torr. & A. Gray) C.L. Hitchc. -- not accepted
  Cortaderia archboldii (Hitchc.) Connor & Edgar -- not accepted
  Cortaderia peruviana (Hitchc.) N. P. Barker & H. P. Linder -- accepted
  Cortaderia sericantha (Steud.) Hitchc. -- accepted
  Corydalis caseana var. cusickii (S. Watson) C.L. Hitchc. -- not accepted
  Corydalis caseana var. hastata (Rydb.) C.L. Hitchc. -- not accepted
  Craspedorhachis texana (Hitchc.) Pilg. -- not accepted
  Craspedorhachis texana var. texana (Hitchc.) Pilg. -- not accepted
  Crotalaria retzii Hitchc. -- not accepted
  Ctenium aromaticum (Walter) Hitchc. -- not accepted
  Ctenium floridanum (Hitchc.) Hitchc. -- accepted -- Florida orangegrass
  Ctenium plumosum (Hitchc.) Swallen -- accepted
  Cuscuta indecora var. neuropetala (Engelm.) Hitchc. -- not accepted -- bigseed alfalfa dodder, bigseed dodder
  Cymbopogon bracteatus (Humb. & Bonpl. ex Willd.) Hitchc. -- not accepted
  Cymbopogon ruprechtii (Hack.) Hitchc. -- not accepted
  Dactylis glomerata var. variegata Hitchc. -- not accepted
  Danthonia archboldii Hitchc. -- not accepted
  Danthonia californica var. americana (Scribn.) Hitchc. -- accepted
  Danthonia cusickii (T.A. Williams) Hitchc. -- not accepted
  Danthonia macounii Hitchc. -- not accepted
  Delphinium menziesii var. pyramidale (Ewan) C.L. Hitchc. -- not accepted
  Delphinium multiplex (Ewan) C.L. Hitchc. -- accepted -- Kittitas larkspur
  Delphinium nuttallianum var. fulvum C.L. Hitchc. -- not accepted -- yellow larkspur
  Delphinium nuttallianum var. levicaule C.L. Hitchc. -- not accepted
  Delphinium nuttallianum var. lineapetalum (Ewan) C.L. Hitchc. -- not accepted -- Nuttal's larkspur
  Delphinium nuttallianum var. pilosa C.L. Hitchc. -- not accepted
  Deschampsia domingensis Hitchc. & Ekman -- accepted
  Deschampsia liebmanniana (E. Fourn.) Hitchc. -- accepted
  Deschampsia straminea Hitchc. -- not accepted
  Descurainia pinnata var. intermedia (Rydb.) C.L. Hitchc. -- not accepted
  Descurainia richardsonii var. sonnei (B.L. Rob.) C.L. Hitchc. -- not accepted
  Desmodium procumbens (Mill.) Hitchc. -- accepted -- western trailing tickclover, western trailing ticktrefoil
  Desmodium procumbens var. procumbens (Mill.) Hitchc. -- accepted -- western trailing ticktrefoil
  Dicanthelium (Hitchc. & Chase) Gould -- not accepted
  Dichanthelium (Hitchc. & Chase) Gould -- accepted -- rosette grass
  Dichanthelium aciculare ssp. fusiforme (Hitchc.) Freckmann & Lelong -- not accepted
  Dichanthelium caerulescens (Hack. ex Hitchc.) Correll -- not accepted
  Dichanthelium chamaelonche ssp. breve (Hitchc. & Chase) Freckmann & Lelong -- not accepted
  Dichanthelium dichotomum var. breve (Hitchc. & Chase) Gould & C.A. Clark -- not accepted -- cypress panicgrass
  Dichanthelium ensifolium var. breve (Hitchc. & Chase) B.F. Hansen & Wunderlin -- accepted
  Dichanthelium forbesii (Hitchc.) C.A. Clark & Gould -- accepted
  Dichanthelium fusiforme (Hitchc.) Harvill -- accepted
  Dichanthelium hillebrandianum (Hitchc.) C.A. Clark & Gould -- accepted -- bog rosette grass
  Dichanthelium nodatum (Hitchc. & Chase) Gould -- accepted -- Sarita rosette grass
  Dichanthelium ovale ssp. praecocius (Hitchc. & Chase) Freckmann & Lelong -- not accepted
  Dichanthelium sabulorum var. thinium (Hitchc. & Chase) Gould & C.A. Clark -- not accepted -- hemlock rosette grass
  Dichanthelium villosissimum var. praecocius (Hitchc. & Chase) Freckmann -- not accepted -- white-hair rosette grass, whitehair rosette grass
  Dichromena colorata (L.) Hitchc. -- not accepted
  Digitaria aequatoriensis (Hitchc.) Henrard -- accepted
  Digitaria argillacea (Hitchc. & Chase) Fernald -- accepted -- tropical crabgrass
  Digitaria argillacea var. argillacea (Hitchc. & Chase) Fernald -- accepted
  Digitaria curtigluma Hitchc. -- accepted
  Digitaria ekmanii Hitchc. -- accepted
  Digitaria floridana Hitchc. -- accepted -- Florida crabgrass
  Digitaria hirtigluma Hitchc. -- not accepted
  Digitaria malacophylla (Hitchc.) Henrard -- not accepted
  Digitaria pauciflora Hitchc. -- accepted -- Florida pineland crabgrass, twospike crabgrass
  Digitaria pinetorum Hitchc. -- accepted
  Digitaria runyonii Hitchc. -- not accepted
  Digitaria subcalva Hitchc. -- not accepted
  Digitaria texana Hitchc. -- accepted -- Texas crabgrass
  Digitaria velutina (DC.) Hitchc. -- not accepted
  Dissanthelium calycinum (J. Presl) Hitchc. -- accepted
  Dissanthelium calycinum ssp. calycinum (J. Presl) Hitchc. -- accepted
  Distichlis stricta var. dentata (Rydb.) C.L. Hitchc. -- not accepted
  Dodecatheon pauciflorum var. alaskanum (Hultén) C.L. Hitchc. -- not accepted
  Dodecatheon pauciflorum var. watsonii (Tidestr.) C.L. Hitchc. -- not accepted
  Dodecatheon pulchellum var. watsonii (Tidestr.) C.L. Hitchc. -- not accepted
  Draba apiculata C.L. Hitchc. -- not accepted
  Draba apiculata var. daviesiae C.L. Hitchc. -- not accepted
  Draba arida C.L. Hitchc. -- accepted -- desert draba
  Draba asprella var. kaibabensis C.L. Hitchc. -- not accepted -- Kaibab draba, Kaibab whitlowgrass
  Draba asprella var. typica C.L. Hitchc. -- not accepted
  Draba asprella var. zionensis (C.L. Hitchc.) S.L. Welsh & Reveal -- not accepted -- Zion draba, Zion whitlowgrass
  Draba asterophora var. macrocarpa C.L. Hitchc. -- not accepted -- Cup Lake draba, Lake Tahoe draba
  Draba aurea var. leiocarpa (Payson & H. St. John) C.L. Hitchc. -- not accepted
  Draba bifurcata (C.L. Hitchc.) Al-Shehbaz & Windham -- accepted -- Heller's draba
  Draba burkei (C.L. Hitchc.) Windham & Beilstein -- accepted -- snowbasin draba
  Draba crassifolia var. nevadensis C.L. Hitchc. -- not accepted -- dolomite draba
  Draba crassifolia var. typica C.L. Hitchc. -- not accepted
  Draba cruciata var. integrifolia C.L. Hitchc. & Sharsm. -- not accepted
  Draba cuneifolia var. typica C.L. Hitchc. -- not accepted
  Draba daviesiae (C.L. Hitchc.) Rollins -- accepted -- bitter root draba
  Draba densifolia var. apiculata (C.L. Hitchc.) S.L. Welsh -- not accepted
  Draba densifolia var. daviesiae (C.L. Hitchc.) S.L. Welsh & Reveal -- not accepted
  Draba douglasii var. crockeri (Lemmon) C.L. Hitchc. -- not accepted
  Draba exunguiculata (O.E. Schulz) C.L. Hitchc. -- accepted -- clawless draba, Garys Peak draba
  Draba grayana (Rydb.) C.L. Hitchc. -- accepted -- Gray's draba
  Draba helleriana var. bifurcata C.L. Hitchc. -- not accepted -- Heller's draba, Heller's whitlowgrass
  Draba helleriana var. blumeri C.L. Hitchc. -- not accepted -- Blumer whitlowgrass, Blumer's draba, Blumer's whitlowgrass
  Draba howellii var. carnosula (O.E. Schulz) C.L. Hitchc. -- not accepted
  Draba lonchocarpa var. thompsonii (C.L. Hitchc.) Rollins -- not accepted -- Thompson's draba
  Draba maguirei C.L. Hitchc. -- accepted -- Maguire's draba
  Draba maguirei var. burkei C.L. Hitchc. -- not accepted -- Burke's draba
  Draba maguirei var. maguirei C.L. Hitchc. -- not accepted -- Maguire's draba
  Draba nivalis var. denudata (O.E. Schulz) C.L. Hitchc. -- not accepted
  Draba nivalis var. exigua (O.E. Schulz) C.L. Hitchc. -- not accepted
  Draba nivalis var. thompsonii C.L. Hitchc. -- not accepted
  Draba oligosperma var. pectinipila (Rollins) C.L. Hitchc. -- not accepted
  Draba pancifructa Clokey & C.L. Hitchc. -- not accepted
  Draba paucifructa Clokey & C.L. Hitchc. -- accepted -- Charleston draba, Charleston Mountain draba
  Draba paysonii var. treleasii (O.E. Schulz) C.L. Hitchc. -- not accepted -- Trelease's draba
  Draba petrophila var. viridis (A. Heller) C.L. Hitchc. -- not accepted -- Santa Rita Mountain draba, Santa Rita whitlowgrass
  Draba rectifructa C.L. Hitchc. -- accepted -- mountain draba, mountain whitlowgrass
  Draba reptans var. stellifera (O.E. Schulz) C.L. Hitchc. -- not accepted
  Draba reptans var. typica C.L. Hitchc. -- not accepted
  Draba spectabilis var. dasycarpa (O.E. Schulz) C.L. Hitchc. -- not accepted
  Draba spectabilis var. typica C.L. Hitchc. -- not accepted
  Draba sphaeroides var. cusickii (B.L. Rob. ex O.E. Schulz) C.L. Hitchc. -- not accepted
  Draba stenoloba var. nana (O.E. Schulz) C.L. Hitchc. -- not accepted
  Draba stenoloba var. ramosa C.L. Hitchc. -- not accepted -- Alaska draba
  Draba subalpina Goodman & C.L. Hitchc. -- accepted -- subalpine draba
  Draba ventosa var. ruaxes (Payson & H. St. John) C.L. Hitchc. -- not accepted
  Draba zionensis C.L. Hitchc. -- accepted -- Zion draba
  Dryas octopetala ssp. octopetala var. angustifolia C.L. Hitchc. -- not accepted -- eightpetal mountain-avens
  Dryas octopetala var. angustifolia C.L. Hitchc. -- not accepted -- eightpetal mountain-avens
  Drymocallis campanulata (C.L. Hitchc.) Ertter -- accepted -- John Day drymocallis
  Dyssodia papposa (Vent.) Hitchc. -- accepted -- dogbane dyssodia, dogweed, fetid dogweed, fetid marigold, fetid-marigold, prairie dogweed
  Echinochloa crus-galli ssp. edulis (Hitchc.) Honda -- not accepted
  Echinochloa crus-galli var. crus-pavonis (Kunth) Hitchc. -- not accepted
  Echinochloa crus-galli var. zelayensis (Kunth) Hitchc. -- accepted
  Echinochloa crusgalli var. cruspavonis (Kunth) Hitchc. -- not accepted
  Echinochloa crusgalli var. edulis Hitchc. -- not accepted
  Echinochloa crusgalli var. zelayensis (Kunth) Hitchc. -- not accepted
  Echinochloa oplismenoides (E. Fourn.) Hitchc. -- accepted -- Chihuahuan cockspur
  Echinochloa polystachya (Kunth) Hitchc. -- accepted -- creeping river grass, creeping rivergrass
  Echinochloa polystachya var. polystachya (Kunth) Hitchc. -- accepted
  Echinochloa pyramidalis (Lam.) Hitchc. & Chase -- accepted -- antelope grass
  Echinochloa sabulicola (Nees) Hitchc. -- not accepted
  Echinolaena standleyi (Hitchc.) Stieber -- accepted
  Ekmanochloa Hitchc. -- accepted
  Ekmanochloa subaphylla Hitchc. -- accepted
  Elmera racemosa var. puberulenta C.L. Hitchc. -- not accepted -- yellow coralbells
  Elymus ambiguus var. salina (M.E. Jones) C.L. Hitchc. -- not accepted
  Elymus ambiguus var. salinus (M.E. Jones) C.L. Hitchc. -- not accepted
  Elymus ambiguus var. salmonis C.L. Hitchc. -- not accepted
  Elymus ambiguus var. strigosus (Rydb.) Hitchc. -- not accepted
  Elymus breviaristatus (Hitchc.) Á. Löve -- not accepted
  Elymus cinereus var. pubens (Piper) C.L. Hitchc. -- not accepted
  Elymus glaucus var. aristatus (Merr. (pro sp.)) Hitchc. -- not accepted
  Elymus hirtiflorus Hitchc. -- not accepted
  Elymus striatus var. arkansanus (Scribn. & C.R. Ball) Hitchc. -- not accepted
  Elymus tricoides var. simplex (Scribn. & Williams) A.S. Hitchc. -- not accepted
  Elymus triticoides var. pubescens Hitchc. -- not accepted
  Elymus triticoides var. simplex (Scribn. & T.A. Williams) Hitchc. -- not accepted
  Elymus virginicus var. australis (Scribn. & C.R. Ball) Hitchc. -- not accepted
  Elymus virginicus var. hirsutiglumis (Scribn.) Hitchc. -- not accepted
  Elymus X hirtiflorus Hitchc. -- not accepted
  Elytrigia breviaristata (Hitchc.) Covas ex J.H. Hunz. & Xifreda -- not accepted
  Elytrigia breviaristata (Hitchc.) Covas -- not accepted
  Epicampes emersleyi (Vasey) Hitchc. -- not accepted
  Epicampes subpatens Hitchc. -- not accepted
  Epilobium alpinum var. albiflorum (Suksd.) C.L. Hitchc. -- not accepted
  Epilobium alpinum var. clavatum (Trel.) C.L. Hitchc. -- not accepted
  Epilobium alpinum var. gracillimum (Trel.) C.L. Hitchc. -- not accepted
  Epilobium alpinum var. lactiflorum (Hausskn.) C.L. Hitchc. -- not accepted
  Epilobium glandulosum var. macounii (Trel.) C.L. Hitchc. -- not accepted
  Epilobium glandulosum var. tenue (Trel.) C.L. Hitchc. -- not accepted
  Epilobium watsonii var. occidentale (Trel.) C.L. Hitchc. -- not accepted
  Epilobium watsonii var. parishii (Trel.) C.L. Hitchc. -- not accepted
  Eragrostis acuta Hitchc. -- not accepted
  Eragrostis arida Hitchc. -- not accepted
  Eragrostis attenuata Hitchc. -- accepted
  Eragrostis bahamensis Hitchc. -- accepted
  Eragrostis chariis (Schult.) Hitchc. -- not accepted
  Eragrostis cubensis Hitchc. -- accepted
  Eragrostis deflexa Hitchc. -- accepted -- Pacific lovegrass
  Eragrostis diffusa var. arida (Hitchc.) Beetle -- not accepted
  Eragrostis ekmanii Hitchc. -- not accepted
  Eragrostis falcata sensu Hitchc., non Gaudich. ex Steud. -- not accepted
  Eragrostis floridana Hitchc. -- not accepted
  Eragrostis guianensis Hitchc. -- accepted
  Eragrostis intermedia Hitchc. -- accepted -- plains lovegrass
  Eragrostis intermedia var. intermedia Hitchc. -- accepted
  Eragrostis leptophylla Hitchc. -- accepted -- mountain lovegrass
  Eragrostis magna Hitchc. -- accepted
  Eragrostis mauiensis Hitchc. -- accepted -- Maui lovegrass
  Eragrostis pectinacea var. tracyi (Hitchc.) P.M. Peterson -- accepted -- Sanibel Island lovegrass
  Eragrostis pilgeriana Hitchc. -- not accepted
  Eragrostis scribneriana Hitchc. -- not accepted
  Eragrostis swallenii Hitchc. -- accepted -- Swallen's lovegrass
  Eragrostis tracyi Hitchc. -- not accepted -- Sanibel Island lovegrass
  Eragrostis trichocolea var. floridana (Hitchc.) Witherspoon -- not accepted -- hairysheath lovegrass
  Eragrostis urbaniana Hitchc. -- accepted -- Urban's lovegrass
  Erianthus divaricatus (L.) Hitchc. -- not accepted
  Eriochloa aristata var. boxiana (Hitchc.) R.B. Shaw -- accepted
  Eriochloa boxiana Hitchc. -- not accepted
  Eriochloa contracta Hitchc. -- accepted -- prairie cupgrass
  Eriochloa eggersii Hitchc. -- accepted
  Eriochloa ekmanii Hitchc. -- not accepted
  Eriochloa filifolia Hitchc. -- not accepted
  Eriochloa gracilis (E. Fourn.) Hitchc. -- not accepted -- southwestern cupgrass, tapertip cupgrass
  Eriochloa gracilis var. gracilis (E. Fourn.) Hitchc. -- not accepted
  Eriochloa gracilis var. minor (Vasey) Hitchc. -- not accepted
  Eriochloa michauxii (Poir.) Hitchc. -- accepted -- longleaf cupgrass
  Eriochloa michauxii var. michauxii (Poir.) Hitchc. -- accepted -- longleaf cupgrass
  Eriochloa michauxii var. simpsonii (Hitchc.) Hitchc. -- accepted -- Simpson's cupgrass
  Eriochloa setosa (A. Rich.) Hitchc. -- accepted
  Eriochloa setosa var. ekmanii (Hitchc.) R.B. Shaw -- accepted
  Eriochloa setosa var. setosa (A. Rich.) Hitchc. -- accepted
  Eriochloa subglabra (Nash) Hitchc. -- not accepted
  Eriogonum deflexum var. multipedunculatum (S. Stokes) C.L. Hitchc. -- not accepted
  Eriogonum douglasii var. tenue (Small) C.L. Hitchc. -- not accepted
  Eriogonum ovalifolium var. orthocaulon (Small) C.L. Hitchc. -- not accepted
  Eriogonum strictum ssp. proliferum var. glabrum C.L. Hitchc. -- not accepted -- Blue Mountain buckwheat
  Eriogonum strictum ssp. proliferum var. proliferum (Torr. & A. Gray) C.L. Hitchc. -- not accepted -- Blue Mountain buckwheat
  Eriogonum strictum var. flavissimum (Gand.) C.L. Hitchc. -- not accepted
  Eriogonum strictum var. glabrum C.L. Hitchc. -- not accepted -- Blue Mountain buckwheat
  Eriogonum strictum var. proliferum (Torr. & A. Gray) C.L. Hitchc. -- accepted -- Blue Mountain buckwheat
  Eriogonum umbellatum var. aridum (Greene) C.L. Hitchc. -- not accepted
  Eriogonum umbellatum var. hypoleium (Piper) C.L. Hitchc. -- accepted -- sulphur-flower buckwheat
  Erysimum arenicola var. torulosum (Piper) C.L. Hitchc. -- not accepted -- cascade wallflower
  Erythronium grandiflorum var. nudipetalum (Applegate) C.L. Hitchc. -- not accepted
  Euchlaena perennis Hitchc. -- not accepted
  Eulalia japonica var. gracillima (Hitchc.) Grier -- not accepted
  Euphorbia blodgettii Engelm. ex Hitchc. -- accepted -- limestone sandmat
  Euphorbia pilulifera var. obliterata (Jacq.) Hitchc. -- not accepted
  Festuca californica var. parishii (Piper) Hitchc. -- not accepted -- California fescue
  Festuca elmeri var. conferta (Hack. ex Beal) Hitchc. -- not accepted
  Festuca hawaiiensis Hitchc. -- accepted -- Hawai'i fescue
  Festuca hawiiensis Hitchc. -- not accepted
  Festuca idahoensis var. oregona (Hack. ex Beal) C.L. Hitchc. -- not accepted
  Festuca kingii var. rabiosa (Piper) Hitchc. -- not accepted
  Festuca lugens (E. Fourn.) Hitchc. ex Hern.-Xol. -- accepted
  Festuca nigriflora (Hitchc.) Negritto & Anton -- accepted
  Festuca octoflora var. hirtella (Piper) Hitchc. -- not accepted
  Festuca ovina var. brachyphylla (Schult. & Schult. f.) Hitchc. -- not accepted
  Festuca parishii (Piper) Hitchc. -- not accepted -- Parish's California fescue
  Festuca parvipaniculata Hitchc. -- accepted
  Festuca presliana Hitchc. -- accepted
  Festuca rubra var. densiuscula (Hack. ex Piper) Hitchc. -- not accepted
  Festuca tracyi Hitchc. -- not accepted
  Fluminia festucacea (Willd.) Hitchc. -- not accepted
  Fragaria vesca var. crinita (Rydb.) C.L. Hitchc. -- not accepted
  Frasera albicaulis var. columbiana (H. St. John) C.L. Hitchc. -- accepted -- whitestem frasera
  Frasera albicaulis var. cusickii (A. Gray) C.L. Hitchc. -- accepted -- Cusick's frasera
  Frasera albicaulis var. idahoensis (H. St. John) C.L. Hitchc. -- accepted -- Idaho frasera
  Frasera albicaulis var. nitida (Benth.) C.L. Hitchc. -- accepted -- whitestem frasera
  Gentiana calycosa var. asepala (Maguire) C.L. Hitchc. -- not accepted
  Gentiana calycosa var. obtusiloba (Rydb.) C.L. Hitchc. -- not accepted
  Gentiana detonsa var. unicaulis (A. Nelson) C.L. Hitchc. -- not accepted
  Geranium viscosissimum var. nervosum (Rydb.) C.L. Hitchc. -- not accepted -- sticky purple geranium
  Geum rossii var. depressum (Greene) C.L. Hitchc. -- not accepted -- Ross' avens
  Geum rossii var. turbinatum (Rydb.) C.L. Hitchc. -- not accepted -- Ross' avens
  Geum triflorum var. campanulatum (Greene) C.L. Hitchc. -- not accepted -- old man's whiskers
  Glossopetalon nevadense var. stipuliferum (H. St. John) C.L. Hitchc. -- not accepted
  Glyceria canadensis var. laxa (Scribn.) Hitchc. -- accepted
  Glyceria elata (Nash) Hitchc. -- not accepted
  Glyceria erecta Hitchc. -- not accepted
  Glyceria fernaldii (Hitchc.) H. St. John -- not accepted
  Glyceria otisii Hitchc. -- not accepted -- Washington mannagrass
  Glyceria pallida var. fernaldii Hitchc. -- not accepted
  Glyceria septentrionalis Hitchc. -- accepted -- floating mannagrass
  Glyceria septentrionalis var. septentrionalis Hitchc. -- accepted
  Glyceria striata (Lam.) Hitchc. -- accepted -- fowl manna grass, fowl mannagrass
  Glyceria striata var. striata (Lam.) Hitchc. -- accepted -- fowl mannagrass
  Glyceria torreyana (Spreng.) Hitchc. -- not accepted
  Godetia amoena var. gracilis C.L. Hitchc. -- not accepted
  Godetia amoena var. sonomensis C.L. Hitchc. -- not accepted
  Godetia bottae var. deflexa (Jeps.) C.L. Hitchc. -- not accepted
  Godetia cylindrica (Jeps.) C.L. Hitchc. -- not accepted
  Godetia parviflora var. luteola C.L. Hitchc. -- not accepted
  Godetia parviflora var. margaritiae C.L. Hitchc. -- not accepted
  Godetia purpurea var. parviflora (S. Watson) C.L. Hitchc. -- not accepted
  Gouinia brandegei (Vasey) Hitchc. -- not accepted
  Gymnopogon aristiglumis Hitchc. -- accepted
  Gymnopogon chapmanianus Hitchc. -- accepted -- Chapman's skeletongrass
  Gymnopogon fastigiatus ssp. jubiflorus (Hitchc.) J.P. Smith -- accepted
  Gymnopogon jubiflorus Hitchc. -- not accepted
  Halimolobos perplexa var. lemhiensis C.L. Hitchc. -- not accepted -- Lemhi halimolobos
  Halimolobos perplexus var. lemhiensis C.L. Hitchc. -- not accepted -- Lemhi halimolobos
  Haplopappus megacephalus (Nash) A. Hitchc. -- not accepted
  Hedysarum boreale var. mackenziei (Richardson) C.L. Hitchc. -- not accepted
  Helictotrichon bulbosum (Hitchc.) Parodi -- not accepted
  Hesperostipa curtiseta (Hitchc.) Barkworth -- accepted -- Canadian needle grass, shortbristle needle and thread
  Hesperostipa saxicola (Hitchc.) Valdés-Reyna & Barkworth -- accepted
  Heuchera grossulariifolia var. tenuifolia (Wheelock) C.L. Hitchc. -- not accepted -- gooseberryleaf alumroot
  Hierochloe mexicana (Rupr. ex E. Fourn.) Benth. ex Hitchc. -- not accepted
  Hilaria belangeri var. longifolia (Vasey) Hitchc. -- accepted -- longleaf curly mesquite, longleaf curly-mesquite
  Holcus sorghum ssp. drummondii (Nees ex Steud.) Hitchc. -- not accepted
  Holcus sorghum ssp. verticilliflorus (Steud.) Hitchc. -- not accepted
  Holcus sorghum var. drummondii (Nees ex Steud.) Hitchc. -- not accepted
  Holcus sorghum var. sudanensis (Piper) Hitchc. -- not accepted
  Holodiscus dumosus var. glabrescens (Greenm.) C.L. Hitchc. -- not accepted
  Homalocenchrus grandiflorus (Döll) Hitchc. -- not accepted
  Hordeum jubatum var. boreale (Hitchc.) B. Boivin -- not accepted
  Hordeum jubatum var. caespitosum (Scribn.) Hitchc. -- not accepted
  Hordeum nodosum var. boreale Hitchc. -- not accepted
  Hordeum pusillum var. pubens Hitchc. -- not accepted
  Hyparrhenia eberhardtii (A. Camus) Hitchc. -- not accepted
  Hypericum formosum ssp. scouleri (Hook.) C.L. Hitchc. -- not accepted
  Hypericum formosum var. nortoniae (M.E. Jones) C.L. Hitchc. -- not accepted
  Hypogynium contracta (Kunth) Hitchc. -- not accepted
  Ichnanthus axillaris (Nees) Hitchc. & Chase -- not accepted
  Ichnanthus conjunctus Hitchc. & Ekman -- not accepted
  Ichnanthus glaber (Raddi) Hitchc. -- accepted
  Ichnanthus ichnodes (Griseb.) Hitchc. & Chase -- not accepted
  Ichnanthus mayarensis (C. Wright) Hitchc. -- accepted
  Ichnanthus nemoralis (Schrad.) Hitchc. & Chase -- accepted
  Ichnanthus standleyi Hitchc. -- not accepted
  Ichnanthus tenuis (J. Presl & C. Presl) Hitchc. & Chase -- accepted -- forest bedgrass
  Ichnanthus wrightii Hitchc. -- not accepted
  Ichthyomethia piscipula (L.) Hitchc. -- not accepted
  Imperata contracta (Kunth) Hitchc. -- accepted -- guayanilla
  Ischaemum byrone (Trin.) Hitchc. -- accepted -- Hilo ischaemum, Hilo murainagrass
  Ischaemum latifolium ssp. hirtivaginum Hitchc. -- not accepted
  Jarava macbridei (Hitchc.) Peńailillo -- accepted
  Jarava milleana (Hitchc.) Peńailillo -- accepted
  Juncus covillei var. obtusatus C.L. Hitchc. -- accepted -- Coville's rush
  Juncus drummondii var. subtriflorus (E. Mey.) C.L. Hitchc. -- not accepted -- threeflower rush
  Juncus ensifolius var. montanus (Engelm.) C.L. Hitchc. -- not accepted -- Rocky Mountain rush
  Juncus nevadensis var. badius (Suksd.) C.L. Hitchc. -- not accepted -- Nevada rush, Sierra rush, Sierran rush
  Juncus nevadensis var. inventus (L.F. Hend.) C.L. Hitchc. -- not accepted -- Sierra rush
  Lactuca spicata auct. non (Lam.) Hitchc. -- not accepted
  Lamprothyrsus peruvianus Hitchc. -- not accepted
  Lasiacis (Griseb.) Hitchc. -- accepted -- smallcane
  Lasiacis anomala Hitchc. -- accepted
  Lasiacis compacta (Sw. ex Wikstr.) Hitchc. -- not accepted
  Lasiacis dicaricata (L.) Hitchc. -- not accepted
  Lasiacis divaricata (L.) Hitchc. -- accepted -- smallcane
  Lasiacis divaricata var. divaricata (L.) Hitchc. -- accepted
  Lasiacis divaricata var. leptostachya (Hitchc.) Davidse -- accepted
  Lasiacis globosa Hitchc. -- not accepted
  Lasiacis grisebachii (Nash) Hitchc. -- accepted -- Grisebach's tribisee
  Lasiacis grisebachii var. grisebachii (Nash) Hitchc. -- accepted
  Lasiacis leptostachya Hitchc. -- not accepted
  Lasiacis liebmanniana (E. Fourn.) Hitchc. -- not accepted
  Lasiacis ligulata Hitchc. & Chase -- accepted -- thicket tribisee
  Lasiacis oaxacensis (Steud.) Hitchc. -- accepted
  Lasiacis oaxacensis var. oaxacensis (Steud.) Hitchc. -- accepted
  Lasiacis patentiflora Hitchc. & Chase -- not accepted
  Lasiacis procerrima (Hack.) Hitchc. -- accepted
  Lasiacis rhizophora (E. Fourn.) Hitchc. -- accepted
  Lasiacis rugelii (Griseb.) Hitchc. -- accepted
  Lasiacis rugelii var. rugelii (Griseb.) Hitchc. -- accepted
  Lasiacis ruscifolia (Kunth) Hitchc. & Chase -- not accepted -- climbing tribisee
  Lasiacis ruscifolia (Kunth) Hitchc. -- accepted
  Lasiacis ruscifolia var. ruscifolia (Kunth) Hitchc. -- accepted
  Lasiacis scabrior Hitchc. -- accepted
  Lasiacis sloanei (Griseb.) Hitchc. -- accepted -- Sloane's tribisee
  Lasiacis sorghoidea (Desv. ex Ham.) Hitchc. & Chase -- accepted -- woodland tribisee
  Lasiacis sorghoidea var. patentiflora (Hitchc. & Chase) Davidse -- not accepted -- woodland tribisee
  Lasiacis sorghoidea var. sorghoidea (Desv. ex Ham.) Hitchc. & Chase -- not accepted -- woodland tribisee
  Lasiacis standleyi Hitchc. -- accepted
  Lasiacis swartziana (Hitchc.) Hitchc. -- not accepted
  Lathyrus brachycalyx ssp. zionis (C.L. Hitchc.) S.L. Welsh -- not accepted -- bush pea, bush peavine
  Lathyrus brachycalyx var. zionis (C.L. Hitchc.) S.L. Welsh -- accepted -- bush pea
  Lathyrus delnorticus C.L. Hitchc. -- accepted -- Del Norte pea
  Lathyrus holochlorus (Piper) C.L. Hitchc. -- accepted -- thinleaf pea
  Lathyrus jepsonii ssp. californicus (S. Watson) C.L. Hitchc. -- not accepted -- California pea
  Lathyrus laetiflorus ssp. barbarae (T.G. White) C.L. Hitchc. -- not accepted
  Lathyrus laetiflorus ssp. glaber C.L. Hitchc. -- not accepted
  Lathyrus leucanthus var. laetivirens (Greene ex Rydb.) C.L. Hitchc. -- not accepted
  Lathyrus nevadensis ssp. cusickii (S. Watson) C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus nevadensis ssp. lanceolatus (Howell) C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus nevadensis ssp. lanceolatus var. lanceolatus (Howell) C.L. Hitchc. -- not accepted
  Lathyrus nevadensis ssp. lanceolatus var. nuttallii (S. Watson) C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus nevadensis ssp. lanceolatus var. parkeri (H. St. John) C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus nevadensis ssp. lanceolatus var. pilosellus (M. Peck) C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus nevadensis ssp. lanceolatus var. puniceus C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus nevadensis var. nuttallii (S. Watson) C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus nevadensis var. parkeri (H. St. John) C.L. Hitchc. -- accepted -- Sierra pea
  Lathyrus nevadensis var. pilosellus (M. Peck) C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus nevadensis var. puniceus C.L. Hitchc. -- not accepted -- Sierra pea
  Lathyrus polymorphus ssp. incanus (J.G. Sm. & Rydb.) C.L. Hitchc. -- not accepted -- hoary pea, hoary vetchling
  Lathyrus polymorphus ssp. polymorphus var. hapemanii (A. Nelson) C.L. Hitchc. -- not accepted -- manystem pea
  Lathyrus polymorphus var. hapemanii (A. Nelson) C.L. Hitchc. -- not accepted -- manystem pea
  Lathyrus venosus ssp. arkansanus (Fassett) C.L. Hitchc. -- not accepted
  Lathyrus vestitus ssp. bolanderi (S. Watson) C.L. Hitchc. -- not accepted -- Bolander's pea
  Lathyrus vestitus ssp. ochropetalus (Piper) C.L. Hitchc. -- not accepted
  Lathyrus vestitus ssp. puberulus (T.G. White ex Greene) C.L. Hitchc. -- not accepted
  Lathyrus vestitus var. puperulus (T.G. White ex Greene) C.L. Hitchc. -- not accepted
  Lathyrus zionis C.L. Hitchc. -- not accepted
  Ledum glandulosum ssp. australe C.L. Hitchc. -- not accepted
  Ledum glandulosum ssp. columbianum (Piper) C.L. Hitchc. -- not accepted
  Ledum glandulosum ssp. olivaceum C.L. Hitchc. -- not accepted
  Ledum glandulosum var. californicum (Kellogg) C.L. Hitchc. -- not accepted
  Ledum glandulosum var. columbianum (Piper) C.L. Hitchc. -- not accepted
  Leersia grandiflora (Döll) Hitchc. -- not accepted
  Lepidium alyssoides var. angustifolium (C.L. Hitchc.) Rollins -- not accepted -- mesa pepperwort, mountain pepperweed
  Lepidium campestre var. heterophyllum (S. Watson) C.L. Hitchc. -- not accepted
  Lepidium campestre var. integrifolium (Nutt.) C.L. Hitchc. -- not accepted
  Lepidium densiflorum var. bourgeauanum (Thell.) C.L. Hitchc. -- not accepted
  Lepidium flavum var. felipense C.L. Hitchc. -- not accepted -- Borrego Valley peppergrass, yellow pepperweed
  Lepidium lasiocarpum var. cinereum (C.L. Hitchc.) C.L. Hitchc. -- not accepted
  Lepidium lasiocarpum var. georginum (Rydb.) C.L. Hitchc. -- not accepted
  Lepidium lasiocarpum var. orbiculare (Thell.) C.L. Hitchc. -- not accepted
  Lepidium lasiocarpum var. rotundum C.L. Hitchc. -- not accepted
  Lepidium lasiocarpum var. typicum C.L. Hitchc. -- not accepted
  Lepidium lasiocarpum var. wrightii (A. Gray) C.L. Hitchc. -- not accepted -- Wright's pepperweed
  Lepidium montanum ssp. alyssoides (A. Gray) C.L. Hitchc. -- not accepted
  Lepidium montanum ssp. canescens (Thell.) C.L. Hitchc. -- not accepted
  Lepidium montanum ssp. cinereum (C.L. Hitchc.) C.L. Hitchc. -- not accepted
  Lepidium montanum ssp. davisii (Rollins) C.L. Hitchc. -- not accepted
  Lepidium montanum ssp. demissum C.L. Hitchc. -- not accepted
  Lepidium montanum var. angustifolium C.L. Hitchc. -- not accepted
  Lepidium montanum var. canescens (Thell.) C.L. Hitchc. -- not accepted -- gray pepperweed, mountain pepperweed
  Lepidium montanum var. cinereum (C.L. Hitchc.) Rollins -- not accepted -- mountain pepperweed
  Lepidium montanum var. eastwoodiae (Wooton) C.L. Hitchc. -- not accepted
  Lepidium montanum var. glabrum C.L. Hitchc. -- not accepted -- mountain pepperweed, smooth pepperweed
  Lepidium montanum var. heterophyllum (S. Watson) C.L. Hitchc. -- not accepted
  Lepidium montanum var. integrifolium (Nutt.) C.L. Hitchc. -- not accepted
  Lepidium montanum var. jonesii (Rydb.) C.L. Hitchc. -- not accepted -- Jones pepperweed, Jones' pepperweed
  Lepidium montanum var. spathulatum (B.L. Rob.) C.L. Hitchc. -- not accepted
  Lepidium montanum var. spatulatum (B.L. Rob.) C.L. Hitchc. -- not accepted
  Lepidium montanum var. tenellum (L.O. Williams) C.L. Hitchc. -- not accepted -- mountain pepperweed
  Lepidium montanum var. wyomingense (C.L. Hitchc.) C.L. Hitchc. -- not accepted -- mountain pepperweed
  Lepidium nitidum var. howellii C.L. Hitchc. -- not accepted -- Howell's pepperweed
  Lepidium nitidum var. oreganum (Howell ex Greene) C.L. Hitchc. -- not accepted -- shining pepperweed
  Lepidium oblongum var. insulare C.L. Hitchc. -- not accepted -- veiny pepperweed
  Lepidium pinnatisectum (O.E. Schulz) C.L. Hitchc. -- accepted -- tansy pepperweed
  Lepidium virginicum var. medium (Greene) C.L. Hitchc. -- not accepted -- intermediate pepperweed, medium pepperweed
  Lepidium virginicum var. menziesii (DC.) C.L. Hitchc. -- not accepted -- Menzies' pepperweed
  Lepidium virginicum var. robinsonii (Thell.) C.L. Hitchc. -- not accepted -- Robinson's pepperweed
  Lepidium virginicum var. typicum C.L. Hitchc. -- not accepted
  Leptochloa brandegei (Vasey) Hitchc. -- not accepted
  Leptochloa panicoides (J. Presl) Hitchc. -- accepted -- Amazon sprangletop
  Leptochloa uninervia (J. Presl) Hitchc. & Chase -- not accepted -- Mexican sprangletop
  Leptochloopsis condensata (Hitchc.) H.O. Yates -- not accepted
  Lepturidium Hitchc. & Ekman -- accepted
  Lepturidium insulare Hitchc. & Ekman -- accepted
  Lesquerella alpina var. condensata (A. Nelson) C.L. Hitchc. -- not accepted
  Lesquerella alpina var. laevis (Payson) C.L. Hitchc. -- not accepted
  Lesquerella kingii var. sherwoodii (M. Peck) C.L. Hitchc. -- not accepted
  Lesquerella occidentalis var. cusickii (M.E. Jones) C.L. Hitchc. -- not accepted
  Lesquerella occidentalis var. diversifolia (Greene) C.L. Hitchc. -- not accepted
  Lewisia columbiana ssp. wallowensis (C.L. Hitchc.) J.E. Hohn ex B. Mathew -- not accepted
  Lewisia columbiana var. rupicola (English) C.L. Hitchc. -- accepted -- Columbian lewisia
  Lewisia columbiana var. wallowensis C.L. Hitchc. -- accepted -- Wallowa lewisia
  Leymus salina ssp. salmonis (C.L. Hitchc.) R.J. Atkins -- accepted
  Leymus salinus ssp. salmonis (C.L. Hitchc.) R.J. Atkins -- not accepted -- saline wildrye, Salmon wildrye
  Lithophragma tenellum var. thompsonii (Hoover) C.L. Hitchc. -- not accepted
  Lithospermum gmelini (Michx.) Hitchc. -- not accepted
  Lotus crassifolius var. subglaber (Ottley) C.L. Hitchc. -- not accepted
  Lupinus argenteus var. depressus (Rydb.) C.L. Hitchc. -- not accepted
  Lupinus argenteus var. parviflorus (Nutt. ex Hook. & Arn.) C.L. Hitchc. -- not accepted
  Lupinus latifolius var. thompsonianus (C.P. Sm.) C.L. Hitchc. -- not accepted
  Lupinus lepidus var. cusickii (S. Watson) C.L. Hitchc. -- not accepted
  Lupinus lepidus var. lobbii (A. Gray ex S. Watson) C.L. Hitchc. -- not accepted
  Lupinus lepidus var. utahensis (S. Watson) C.L. Hitchc. -- not accepted
  Lupinus polyphyllus var. burkei (S. Watson) C.L. Hitchc. -- not accepted
  Lupinus sericeus var. asotinensis (L.Ll. Phillips) C.L. Hitchc. -- not accepted
  Lupinus sericeus var. fikeranus (C.P. Sm.) C.L. Hitchc. -- not accepted
  Lupinus sulphureus var. kincaidii (C.P. Sm.) C.L. Hitchc. -- not accepted
  Lupinus sulphureus var. subsaccatus (Suksd.) C.L. Hitchc. -- not accepted
  Luziola bahiensis (Steud.) Hitchc. -- accepted -- Brazilian watergrass
  Luziola bahiensis var. bahiensis (Steud.) Hitchc. -- not accepted
  Lychnis apetala var. attenuata (Farr) C.L. Hitchc. -- not accepted
  Lychnis apetala var. montana (S. Watson) C.L. Hitchc. -- not accepted
  Lycium andersonii var. deserticola (C.L. Hitchc.) C.L. Hitchc. ex Munz -- accepted -- desert Anderson wolfberry, water jacket
  Lycium berlandieri var. brevilobum C.L. Hitchc. -- not accepted
  Lycium berlandieri var. longistylum C.L. Hitchc. -- accepted -- Berlandier wolfberry, Berlandier's wolfberry
  Lycium brevipes var. hassei (Greene) C.L. Hitchc. -- not accepted
  Lycium carolinianum var. quadrifidum (Dunal) C.L. Hitchc. -- accepted -- Carolina desert-thorn, largeflower wolfberry
  Lycium carolinianum var. sandwicense (A. Gray) C.L. Hitchc. -- not accepted
  Lycium pallidum var. oligospermum C.L. Hitchc. -- accepted -- rabbit thorn, rabbitthorn
  Lycium tweedianum var. chrysocarpum (Urb. & Ekman) C.L. Hitchc. -- not accepted -- tropical desert-thorn
  Manisuris altissima (Poir.) Hitchc. -- not accepted
  Manisuris aurita (Steud.) Hitchc. & Chase -- not accepted
  Manisuris campestris (Nutt.) Hitchc. -- not accepted
  Manisuris fasciculata (Lam.) Hitchc. -- not accepted
  Manisuris guianensis Hitchc. -- not accepted
  Manisuris leonina Hitchc. & Chase -- not accepted
  Manisuris ramosa (E. Fourn.) Hitchc. -- not accepted
  Melica alba Hitchc. -- not accepted
  Melica purpurascens (Torr.) Hitchc. -- not accepted
  Melica striata Hitchc. -- not accepted
  Melica subulata var. pammelii (Scribn.) C.L. Hitchc. -- accepted -- Pammel's oniongrass
  Mentzelia laevicaulis var. parviflora (Douglas ex Hook.) C.L. Hitchc. -- accepted -- smoothstem blazingstar
  Mesosetum pittieri Hitchc. -- accepted
  Mesosetum rottboellioides (Kunth) Hitchc. -- accepted
  Mesosetum sclerochloa (Trin.) Hitchc. -- accepted
  Mesosetum wrightii Hitchc. -- accepted
  Miscanthus sinensis f. gracillimus (Hitchc.) Ohwi -- not accepted
  Miscanthus sinensis var. gracillimus A.S. Hitchc. -- not accepted
  Miscanthus sinensis var. gracilliumus Hitchc. -- not accepted
  Montia parvifolia var. flagellaris (Bong.) C.L. Hitchc. -- not accepted
  Muehlenbergia lanata (Kunth) Hitchc. -- not accepted
  Muehlenbergia macroura (Kunth) Hitchc. -- not accepted
  Muehlenbergia pubescens (Kunth) Hitchc. -- not accepted
  Muehlenbergia robusta (E. Fourn.) Hitchc. -- not accepted
  Muehlenbergia torreyana (Schult.) Hitchc. -- not accepted
  Muehlenbergia utilis (Torr.) Hitchc. -- not accepted
  Muhlenbergia alta Hitchc. -- not accepted
  Muhlenbergia andina (Nutt.) Hitchc. -- accepted -- foxtail muhly
  Muhlenbergia arenacea (Buckley) Hitchc. -- accepted -- ear muhly, eared muhly
  Muhlenbergia arsenei Hitchc. -- accepted -- Navajo muhly
  Muhlenbergia biloba Hitchc. -- accepted
  Muhlenbergia breviligula Hitchc. -- accepted
  Muhlenbergia crispiseta Hitchc. -- accepted -- Mexicali muhly
  Muhlenbergia enervis (Scribn. ex Beal) Hitchc. -- not accepted
  Muhlenbergia flexuosa Hitchc. -- accepted
  Muhlenbergia fournieriana Hitchc. -- not accepted
  Muhlenbergia gigantea (E. Fourn.) Hitchc. -- accepted
  Muhlenbergia holwayorum Hitchc. -- not accepted
  Muhlenbergia jonesii (Vasey) Hitchc. -- accepted -- Modoc muhly
  Muhlenbergia lanata (Kunth) Hitchc. -- not accepted
  Muhlenbergia laxa Hitchc. -- accepted
  Muhlenbergia leptoura (Piper) Hitchc. -- not accepted
  Muhlenbergia ligularis (Hack.) Hitchc. -- accepted
  Muhlenbergia lindheimeri Hitchc. -- accepted -- Lindheimer muhly, Lindheimer's muhly
  Muhlenbergia longiligula Hitchc. -- accepted -- longtongue muhly
  Muhlenbergia macrotis (Piper) Hitchc. -- not accepted
  Muhlenbergia macroura (Kunth) Hitchc. -- accepted -- muhly
  Muhlenbergia magna Hitchc. -- not accepted
  Muhlenbergia meziana Hitchc. -- not accepted
  Muhlenbergia minutiflora (Michx.) Hitchc. -- not accepted
  Muhlenbergia montana (Nutt.) Hitchc. -- accepted -- mountain muhly
  Muhlenbergia mutica (Rupr. ex E. Fourn.) Hitchc. -- accepted
  Muhlenbergia nigra Hitchc. -- accepted
  Muhlenbergia plumbea (Trin.) Hitchc. -- accepted
  Muhlenbergia presliana Hitchc. -- not accepted
  Muhlenbergia pubescens (Kunth) Hitchc. -- accepted
  Muhlenbergia quitensis (Kunth) Hitchc. -- not accepted
  Muhlenbergia repens (J. Presl) Hitchc. -- accepted -- creeping muhly, red muhly
  Muhlenbergia rigens (Benth.) Hitchc. -- accepted -- deer muhly, deergrass
  Muhlenbergia robusta (E. Fourn.) Hitchc. -- accepted
  Muhlenbergia sobolifera var. setigera (Scribn.) Hitchc. & Chase -- not accepted
  Muhlenbergia straminea Hitchc. -- accepted
  Muhlenbergia subbiflora Hitchc. -- accepted
  Muhlenbergia torreyana (Schult.) Hitchc. -- accepted -- New Jersey muhly, ring muhly
  Muhlenbergia torreyi (Kunth) Hitchc. ex Bush -- accepted -- ring muhly
  Muhlenbergia utilis (Torr.) Hitchc. -- accepted -- aparejo muhly, aparejograss
  Muhlenbergia villiflora Hitchc. -- accepted -- hairy muhly
  Muhlenbergia villiflora var. villiflora Hitchc. -- accepted
  Muhlenbergia watsoniana Hitchc. -- accepted
  Nama carnosa (Wooton) C.L. Hitchc. -- accepted -- sand fiddleleaf
  Nama carnosum (Wooton) C.L. Hitchc. -- not accepted -- sand fiddleleaf
  Nama densa var. parviflora (Greenm.) C.L. Hitchc. -- accepted -- leafy fiddleleaf
  Nama densum var. parviflorum (Greenm.) C.L. Hitchc. -- not accepted -- leafy fiddleleaf
  Nama hispidum var. spathulatum (Torr.) C.L. Hitchc. -- not accepted
  Nama serpylloides var. velutinum C.L. Hitchc. -- not accepted
  Nama stevensi C.L. Hitchc. -- not accepted
  Nama stevensii C.L. Hitchc. -- accepted -- Stevens' fiddleleaf, Stevens' nama
  Nama xylopoda C.L. Hitchc. -- accepted -- yellowseed fiddleleaf
  Nama xylopodum (Wooton & Standl.) C.L. Hitchc. -- not accepted -- yellowseed fiddleleaf
  Nassella asplundii Hitchc. -- accepted
  Nassella brachyphylla (Hitchc.) Barkworth -- accepted
  Nassella curviseta (Hitchc.) Barkworth -- accepted
  Nassella dasycarpa (Hitchc.) Torres -- accepted
  Nassella hirtifolia (Hitchc.) Barkworth -- accepted
  Nassella holwayii (Hitchc.) Barkworth -- accepted
  Nassella karstenii (Hitchc.) Peńailillo -- accepted
  Nassella lepida (Hitchc.) Barkworth -- accepted -- smallflower tussockgrass
  Nassella mexicana (Hitchc.) R.W. Pohl -- accepted
  Nassella pittieri (Hitchc.) Peńailillo -- accepted
  Nassella pulchra (Hitchc.) Barkworth -- accepted -- purple tussockgrass
  Nassella smithii (Hitchc.) Barkworth -- accepted
  Neurolepis aristata (Munro) Hitchc. -- not accepted
  Neyraudia reynaudiana (Kunth) Keng ex Hitchc. -- accepted -- Burma reed, silk reed, silkreed
  Notholcus Nash ex Hitchc. -- not accepted
  Notholcus lanatus (L.) Nash ex Hitchc. -- not accepted
  Notholcus mollis (L.) Hitchc. -- not accepted
  Olyra sampaiana Hitchc. -- not accepted
  Olyra standleyi Hitchc. -- accepted
  Orcuttia tenuis Hitchc. -- accepted -- slender Orcutt grass
  Ortachne breviseta Hitchc. -- accepted
  Oryzopsis pungens (Torr.) Hitchc. -- not accepted -- mountain ricegrass
  Oryzopsis racemosa (Sm.) Ricker ex Hitchc. -- not accepted
  Oryzopsis swallenii C.L. Hitchc. & Spellenb. -- not accepted
  Osterdamia japonica (Steud.) Hitchc. -- not accepted
  Panicularia erecta (Hitchc.) Hitchc. -- not accepted
  Panicularia fernaldii (Hitchc.) House -- not accepted
  Panicularia fluitans var. septentrionalis (Hitchc.) Farw. -- not accepted
  Panicularia melicaria (Michx.) Hitchc. -- not accepted
  Panicularia nervata var. stricta (Scribn.) Scribn. ex Hitchc. -- not accepted
  Panicularia septentrionalis (Hitchc.) E.P. Bicknell -- not accepted
  Panicularia striata (Lam.) Hitchc. -- not accepted
  Panicum aculeatum Hitchc. & Chase -- not accepted
  Panicum altum Hitchc. & Chase -- accepted
  Panicum amarulum Hitchc. & Chase -- not accepted
  Panicum amarum ssp. amarulum (Hitchc. & Chase) Freckmann & Lelong -- not accepted
  Panicum amarum var. amarulum (Hitchc. & Chase) P. Palmer -- accepted -- bitter panicgrass
  Panicum anceps ssp. rhizomatum (Hitchc. & Chase) Freckmann & Lelong -- not accepted
  Panicum anceps var. rhizomatum (Hitchc. & Chase) Fernald -- not accepted
  Panicum asperifolium (Desv.) Hitchc. -- not accepted
  Panicum beyeri Hitchc. & Ekman -- accepted
  Panicum boscii var. molle (Vasey ex Ward) Hitchc. & Chase -- not accepted
  Panicum breve Hitchc. & Chase -- not accepted
  Panicum bulbosum ssp. sciaphilum (Rupr. ex E. Fourn.) Hitchc. & Chase -- not accepted
  Panicum caerulescens Hack. ex Hitchc. -- not accepted
  Panicum capillare var. pampinosum (Hitchc. & Chase) Gould -- not accepted
  Panicum capillare var. stramineum (Hitchc. & Chase) Gould -- not accepted
  Panicum chamaelonche var. breve (Hitchc. & Chase) Lelong -- not accepted
  Panicum chiriquiense Hitchc. & Chase -- not accepted
  Panicum columbianum var. oricola (Hitchc. & Chase) Fernald -- not accepted
  Panicum columbianum var. siccanum (Hitchc. & Chase) B. Boivin -- not accepted
  Panicum columbianum var. thinium (Hitchc. & Chase) Hitchc. & Chase -- not accepted
  Panicum concinnius Hitchc. & Chase -- not accepted
  Panicum crus-galli var. edule (Hitchc.) Thell. ex de Lesd. -- not accepted
  Panicum crus-galli var. edulis (Hitchc.) Makino & Nemoto -- not accepted
  Panicum cupreum Hitchc. & Chase -- not accepted
  Panicum deamii Hitchc. & Chase -- not accepted
  Panicum decolorans var. parcum (Hitchc. & Chase) Beetle -- not accepted
  Panicum distichum var. lancifolium Griseb. ex Hitchc. -- not accepted
  Panicum eccentricos Hitchc. & Chase ex Rojas -- not accepted
  Panicum ensifolium var. breve (Hitchc. & Chase) Wipff & S.D. Jones -- not accepted
  Panicum errabundum Hitchc. -- not accepted
  Panicum fauriei Hitchc. -- accepted -- Faurie's panicgrass
  Panicum fauriei var. fauriei Hitchc. -- accepted -- Faurie's panicgrass
  Panicum firmulum Hitchc. & Chase -- not accepted
  Panicum forbesii Hitchc. -- not accepted
  Panicum fusiforme Hitchc. -- not accepted
  Panicum grande Hitchc. & Chase -- accepted
  Panicum gravius Hitchc. & Chase -- not accepted
  Panicum guianense Hitchc. -- not accepted
  Panicum heterophyllum var. thinium (Hitchc. & Chase) F.T. Hubb. -- not accepted
  Panicum hillebrandianum Hitchc. -- not accepted
  Panicum hirticaule ssp. stramineum (Hitchc. & Chase) Freckmann & Lelong -- not accepted
  Panicum hirticaule var. pampinosum (Hitchc. & Chase) Beetle -- not accepted
  Panicum hirticaule var. stramineum (Hitchc. & Chase) Beetle -- not accepted -- Sonoran panicgrass
  Panicum hirtivaginum Hitchc. -- not accepted
  Panicum huachucae var. silvicola Hitchc. & Chase -- not accepted
  Panicum ineptum Hitchc. & Chase -- not accepted
  Panicum kaalaense Hitchc. -- accepted
  Panicum killipii Hitchc. -- not accepted
  Panicum lacustre Hitchc. & Ekman -- accepted -- lakeshore panicgrass
  Panicum languidum Hitchc. & Chase -- not accepted
  Panicum lanuginosum var. huachucae (Ashe) Hitchc. -- not accepted
  Panicum lanuginosum var. praecocius (Hitchc. & Chase) Dore -- not accepted
  Panicum lanuginosum var. siccanum Hitchc. & Chase -- not accepted
  Panicum laxiflorum var. strictirameum (Hitchc. & Chase) Beetle -- not accepted
  Panicum laxiflorum var. strictirameum (Hitchc. & Chase) Fernald -- not accepted
  Panicum lepidulum Hitchc. & Chase -- accepted -- scale panicgrass
  Panicum longum Hitchc. & Chase -- accepted
  Panicum luticola Hitchc. -- not accepted
  Panicum magnum Hitchc. -- not accepted
  Panicum milleflorum Hitchc. & Chase -- not accepted
  Panicum nodatum Hitchc. & Chase -- not accepted
  Panicum obtusiglume Hitchc. -- not accepted
  Panicum olivaceum Hitchc. & Chase -- not accepted
  Panicum ophiticola Hitchc. & Ekman -- not accepted
  Panicum oricola Hitchc. & Chase -- not accepted
  Panicum pacificum Hitchc. & Chase -- not accepted
  Panicum paludivagum Hitchc. & Chase -- not accepted
  Panicum pampinosum Hitchc. & Chase -- accepted -- Arizona panicgrass
  Panicum panicoides (P. Beauv.) Hitchc. -- not accepted
  Panicum parcum Hitchc. & Chase -- accepted
  Panicum patulum (Scribn. & Merr.) Hitchc. -- not accepted
  Panicum petersonii Hitchc. & Ekman -- not accepted
  Panicum plenum Hitchc. & Chase -- not accepted
  Panicum praecocius Hitchc. & Chase -- not accepted
  Panicum pyrularium Hitchc. & Chase -- accepted
  Panicum quadriglume (Döll) Hitchc. -- accepted
  Panicum ramosius Hitchc. -- accepted -- Lanai panicgrass
  Panicum rhizomatum Hitchc. & Chase -- not accepted
  Panicum rotundum Hitchc. & Chase -- not accepted
  Panicum sabulorum var. thinium (Hitchc. & Chase) C.F. Reed -- not accepted
  Panicum sphaerocarpon ssp. inflatum (Scribn. & J.G. Sm.) Hitchc. -- not accepted
  Panicum sphaerocarpon var. inflatum (Scribn. & J.G. Sm.) Hitchc. -- not accepted
  Panicum stagnatile Hitchc. & Chase -- accepted
  Panicum stamineum Hitchc. & Chase -- not accepted
  Panicum stevensianum Hitchc. & Chase -- accepted -- Stevens' panicgrass
  Panicum stramineum Hitchc. & Chase -- accepted -- Sonoran panicgrass
  Panicum sucosum Hitchc. & Chase -- not accepted
  Panicum swartzianum Hitchc. -- not accepted
  Panicum unciphyllum var. thinium Hitchc. & Chase -- not accepted
  Panicum vernale Hitchc. & Chase -- not accepted
  Panicum xalapense ssp. strictirameum Hitchc. & Chase -- not accepted
  Panicum xerophilum (Hillebr.) Hitchc. -- accepted -- kakonakona
  Pariana gleasonii Hitchc. -- accepted
  Parnassia fimbriata var. hoodiana C.L. Hitchc. -- not accepted -- fringed grass of Parnassus
  Parnassia fimbriata var. intermedia (Rydb.) C.L. Hitchc. -- not accepted -- fringed grass of Parnassus, intermediate parnassia
  Parnassia kotzebuei var. pumila C.L. Hitchc. & Ownbey -- not accepted -- Kotzebue's grass-of-parnassus
  Parnassia palustris var. montanensis (Fernald & Rydb. ex Rydb.) C.L. Hitchc. -- not accepted -- mountain grass of Parnassus, northern grass-of-Parnassus
  Parthenocissus vitacea (Knerr) Hitchc. -- accepted -- thicket creeper, Virginia creeper, woodbine
  Paspalidium geminatum var. paludivagum (Hitchc. & Chase) Gould -- not accepted -- Egyptian panicgrass, Egyptian panicum
  Paspalidium ophiticola (Hitchc. & Ekman) Davidse & R.W. Pohl -- not accepted
  Paspalidium paludivagum (Hitchc. & Chase) Henrard -- not accepted
  Paspalidium paludivagum (Hitchc. & Chase) Parodi -- not accepted
  Paspalidium paludivagum (Hitchc. & Chase) Pilg. -- not accepted
  Paspalidium paludivagum (Hitchc. & Chase) Herter -- not accepted
  Paspalidium subtransiens (Hitchc. & Ekman) Davidse & R.W. Pohl -- not accepted
  Paspalum ciliiferum (Nash) Hitchc. -- not accepted
  Paspalum killipii (Hitchc.) Zuloaga & Soderstr. -- accepted
  Paspalum laeve var. australe (Nash) Nash ex Hitchc. -- not accepted
  Paspalum olivaceum Hitchc. & Chase -- not accepted
  Paspalum psammophilum Nash ex Hitchc. -- not accepted
  Paspalum reptatum Hitchc. & Chase -- accepted
  Paspalum robustum (Hitchc. & Chase) S. Denham -- accepted
  Paspalum secans Hitchc. & Chase -- not accepted -- slender ditch paspalum
  Paspalum serratum Hitchc. & Chase -- not accepted
  Paspalum setaceum var. psammophilum (Nash ex Hitchc.) D.J. Banks -- accepted
  Paspalum urbanianum Ekman ex Hitchc. -- accepted
  Paspalum wrightii Hitchc. & Chase -- accepted
  Pereilema beyrichianum (Kunth) Hitchc. -- not accepted
  Phalaris tuberosa var. stenoptera (Hack.) Hitchc. -- not accepted
  Philadelphus crinitus (C.L. Hitchc.) S.Y. Hu -- not accepted -- hairy mock orange, Trans-Pecos mock orange, Trans-Pecos mockorange
  Philadelphus maculatus (C.L. Hitchc.) S.Y. Hu -- accepted -- spotted mock orange
  Philadelphus microphyllus ssp. argenteus (Rydb.) C.L. Hitchc. -- not accepted
  Philadelphus microphyllus ssp. argyrocalyx (Wooton) C.L. Hitchc. -- not accepted
  Philadelphus microphyllus ssp. occidentalis (A. Nelson) C.L. Hitchc. -- not accepted
  Philadelphus microphyllus ssp. pumilus (Rydb.) C.L. Hitchc. -- not accepted
  Philadelphus microphyllus ssp. stramineus (Rydb.) C.L. Hitchc. -- not accepted
  Philadelphus microphyllus ssp. typicus C.L. Hitchc. -- not accepted
  Pholiurus incurvatus (L.) Hitchc. -- not accepted
  Phragmites communis var. variegatus Hitchc. ex L.H. Bailey -- not accepted
  Phragmites maximus var. variegatus (Hitchc. ex L.H. Bailey) Moldenke -- not accepted
  Physalis cinerascens (Dunal) Hitchc. -- accepted -- smallflower groundcherry
  Physalis cinerascens var. cinerascens (Dunal) Hitchc. -- accepted -- smallflower groundcherry
  Physaria didymocarpa ssp. lyrata (C.L. Hitchc.) O'Kane -- accepted -- Idaho twinpod
  Physaria didymocarpa var. lyrata C.L. Hitchc. -- not accepted -- Idaho twinpod
  Piptatherum racemosum Ricker ex Hitchc. -- not accepted -- black-seed mountain-rice grass, blackseed ricegrass
  Piptochaetium angustifolium (Hitchc.) Valencia & Costas -- accepted
  Piptochaetium featherstonei (Hitchc.) Tovar -- accepted
  Piptochaetium fimbriatum (Kunth) Hitchc. -- accepted -- pinon ricegrass, pinyon ricegrass
  Piptochaetium fimbriatum var. fimbriatum (Kunth) Hitchc. -- not accepted
  Piptochaetium leianthum (Hitchc.) Beetle -- not accepted
  Piptochaetium mexicanum (Hitchc.) Beetle -- not accepted
  Poa albescens Hitchc. -- not accepted
  Poa brevis Hitchc. -- accepted
  Poa cusickii var. epilis (Scribn.) C.L. Hitchc. -- not accepted
  Poa cusickii var. purpurascens (Vasey) C.L. Hitchc. -- not accepted
  Poa fendleriana ssp. albescens (Hitchc.) Soreng -- accepted -- muttongrass
  Poa gracillima var. multnomae (Piper) C.L. Hitchc. -- not accepted
  Poa griffithsii Hitchc. -- not accepted
  Poa guatemalensis Hitchc. -- not accepted
  Poa involuta Hitchc. -- not accepted
  Poa landuida Hitchc. -- not accepted
  Poa languida Hitchc. -- not accepted
  Poa leptocoma var. paucispicula (Scribn. & Merr.) C.L. Hitchc. -- not accepted
  Poa marcida Hitchc. -- accepted -- withered bluegrass
  Poa merrilliana Hitchc. -- not accepted
  Poa nervosa var. wheeleri (Vasey) C.L. Hitchc. -- not accepted
  Poa nigriflora Hitchc. -- not accepted
  Poa orizabensis Hitchc. -- accepted
  Poa piperi Hitchc. -- accepted -- Piper's bluegrass
  Poa remissa Hitchc. -- not accepted
  Poa rhizomata Hitchc. -- accepted -- rhizome bluegrass
  Poa saltuensis ssp. languida (Hitchc.) A. Haines -- accepted
  Poa saltuensis var. marcida (Hitchc.) B. Boivin -- not accepted
  Poa sandvicensis (Reichardt) Hitchc. -- accepted -- Hawai'i bluegrass, Hawaiian bluegrass
  Poa strictiramea Hitchc. -- accepted -- Big Bend bluegrass, chisos bluegrass
  Poa wrightii (Scribn. & Merr.) Hitchc. -- not accepted
  Podagrostis thurberiana (Hitchc.) Hultén -- accepted
  Podagrostris thurberana (Hitchc.) Hultén -- not accepted
  Polypogon lutosus (Poir.) Hitchc. -- not accepted
  Potentilla concinna var. macounii (Rydb.) C.L. Hitchc. -- not accepted
  Potentilla concinna var. rubripes (Rydb.) C.L. Hitchc. -- not accepted
  Potentilla diversifolia var. perdissecta (Rydb.) C.L. Hitchc. -- not accepted -- mountain-meadow cinquefoil, mountainmeadow cinquefoil
  Potentilla glandulosa var. campanulata C.L. Hitchc. -- not accepted
  Potentilla glandulosa var. intermedia (Rydb.) C.L. Hitchc. -- not accepted
  Potentilla gracilis var. brunnescens (Rydb.) C.L. Hitchc. -- not accepted -- sagebrush cinquefoil, slender cinquefoil
  Potentilla gracilis var. glabrata (Lehm.) C.L. Hitchc. -- not accepted
  Potentilla gracilis var. permollis (Rydb.) C.L. Hitchc. -- not accepted
  Potentilla villosa var. parviflora C.L. Hitchc. -- not accepted
  Puccinellia borreri (Bab.) Hitchc. -- not accepted
  Puccinellia erecta (Hitchc.) Munz -- not accepted
  Puccinellia fernaldii (Hitchc.) E.G. Voss -- not accepted
  Puccinellia ferndalii (Hitchc.) E. G. Voss -- not accepted
  Puccinellia nuttalliana (Schult.) Hitchc. -- accepted -- Nuttall alkaligrass, Nuttall's alkaligrass
  Puccinellia oresigena (Phil.) Hitchc. -- not accepted
  Puccinellia parishii Hitchc. -- accepted -- bog alkaligrass, Parish alkaligrass, Parish's alkali grass
  Puccinellia parvula Hitchc. -- accepted
  Puccinellia pauciflora var. holmii (Beal) C.L. Hitchc. -- not accepted
  Puccinellia pauciflora var. microtheca (Buckley) C.L. Hitchc. -- not accepted
  Puccinellia pumila (Vasey) Hitchc. -- accepted -- dwarf alkaligrass
  Puccinellia pumila auct. non (Vasey) Hitchc. -- not accepted
  Raddia biformis Hitchc. & Chase -- not accepted
  Raddia capillata (Trin.) Hitchc. -- not accepted
  Raddia costaricensis Hitchc. -- not accepted
  Raddia guianensis (Brongn.) Hitchc. -- accepted
  Raddia malmeana (Ekman) Hitchc. -- not accepted
  Raddia sympodica (Döll) Hitchc. -- not accepted
  Raddia urbaniana Hitchc. & Chase -- not accepted
  Ranunculus eschscholtzii var. adoneus (A. Gray) C.L. Hitchc. -- not accepted
  Ranunculus eschscholtzii var. alpinus (S. Watson) C.L. Hitchc. -- not accepted
  Reimarochloa Hitchc. -- accepted -- reimar grass
  Reimarochloa acuta (Flüggé) Hitchc. -- accepted
  Reimarochloa brasiliensis (Spreng.) Hitchc. -- not accepted
  Reimarochloa oligostachya (Munro ex Benth.) Hitchc. -- accepted -- Florida reimar grass
  Rhipidocladum maxonii (Hitchc.) McClure -- accepted
  Rhytachne guianensis (Hitchc.) Clayton -- accepted
  Ribes cereum var. colubrinum C.L. Hitchc. -- accepted -- wax currant
  Ribes cereum var. inebrians (Lindl.) C.L. Hitchc. -- not accepted
  Ribes hendersonii C.L. Hitchc. -- not accepted
  Ribes oxyacanthoides ssp. hendersonii (C.L. Hitchc.) Sinnott -- not accepted -- Henderson's currant, Henderson's gooseberry
  Ribes oxyacanthoides var. hendersonii (C.L. Hitchc.) P.K. Holmgren -- accepted -- Henderson's currant
  Ribes velutinum var. gooddingii (M. Peck) C.L. Hitchc. -- not accepted -- Gooding's gooseberry
  Rorippa armoracia (L.) Hitchc. -- not accepted
  Rorippa curvisiliqua var. lyrata (Nutt.) M. Peck ex C.L. Hitchc. -- not accepted -- lyrateleaf yellowcress
  Rorippa sessiliflora (Nutt.) Hitchc. -- accepted -- stalkless yellowcress
  Rorippa sinuata (Nutt.) Hitchc. -- accepted -- spreading yellowcress
  Rottboellia tuberculosa (Nash) Hitchc. -- not accepted
  Rulac negundo (L.) Hitchc. -- not accepted
  Rumex salicifolius var. mexicanus (Meisn.) C.L. Hitchc. -- not accepted -- Mexican dock, trianglevalve dock, willow dock
  Rytilix Raf. ex Hitchc. -- not accepted
  Saugetia Hitchc. & Chase -- accepted
  Saugetia fasciculata Hitchc. & Chase -- accepted
  Saugetia pleiostachya Hitchc. & Ekman -- accepted
  Saxifraga caespitosa var. subgemmifera (Engl. & Irmsch.) C.L. Hitchc. -- not accepted
  Saxifraga cespitosa var. subgemmifera (Engl. & Irmsch.) C.L. Hitchc. -- not accepted
  Saxifraga integrifolia var. columbiana (Piper) C.L. Hitchc. -- not accepted
  Saxifraga occidentalis var. allenii (Small) C.L. Hitchc. -- not accepted
  Saxifraga occidentalis var. dentata (Engl. & Irmsch.) C.L. Hitchc. -- not accepted
  Saxifraga occidentalis var. idahoensis (Piper) C.L. Hitchc. -- not accepted
  Saxifraga occidentalis var. latipetiolata C.L. Hitchc. -- not accepted
  Saxifraga occidentalis var. rufidula (Small) C.L. Hitchc. -- not accepted
  Saxifraga oregana var. montanensis (Small) C.L. Hitchc. -- not accepted
  Saxifraga oregana var. subpetala (E.E. Nelson) C.L. Hitchc. -- not accepted
  Saxifraga punctata var. cascadensis (Calder & Savile) C.L. Hitchc. -- not accepted
  Schizachne striata (Hitchc.) Hultén -- not accepted
  Schizachyrium mexicanum (Hitchc.) A. Camus -- accepted
  Schizachyrium parvifolium (Hitchc.) Borhidi & Catasús -- accepted
  Schizachyrium reedii (Hitchc. & Ekman) Borhidi & Catasús -- accepted
  Schizachyrium scoparium subvar. reedii (Hitchc. & Ekman) Roberty -- not accepted
  Schizachyrium scoparium var. neomexicanum (Nash) Hitchc. -- accepted
  Scutachne Hitchc. & Chase -- accepted
  Scutachne amphistemon (C. Wright) Hitchc. & Chase -- accepted
  Scutachne dura (Griseb.) Hitchc. & Chase -- accepted
  Sedum lanceolatum var. nesioticum (G.N. Jones) C. Hitchc. -- accepted -- spearleaf stonecrop
  Sedum lanceolatum var. rupicola (G.N. Jones) C. Hitchc. -- not accepted
  Senites capillaris Hitchc. -- not accepted
  Senites haitiensis (Pilg.) Hitchc. & Chase -- not accepted
  Senites latifolia (E. Fourn.) Hitchc. -- not accepted
  Senites latifolia ssp. pringlei (Hack.) Hitchc. -- not accepted
  Senites mexicana (Kunth) Hitchc. -- not accepted
  Senites pringlei (Scribn.) Hitchc. -- not accepted
  Senites smilacifolia (Scribn.) Hitchc. -- not accepted
  Setaria carnei Hitchc. -- not accepted
  Setaria firmula (Hitchc. & Chase) Pilg. -- not accepted -- knot grass, knotgrass panicum
  Setaria geminata var. paludivaga (Hitchc. & Chase) R.D. Webster -- not accepted
  Setaria germinata var. paludivaga (Hitchc. & Chase) R.D. Webster -- not accepted
  Setaria imberbis var. perennis (Hall ex Smyth) Hitchc. -- not accepted
  Setaria ophiticola (Hitchc. & Ekman) León -- not accepted
  Setaria reverchonii ssp. firmula (Hitchc. & Chase) W.E. Fox -- accepted
  Setaria scheelei (Steud.) Hitchc. -- accepted -- southwestern bristlegrass
  Setaria subtransiens Hitchc. & Ekman -- not accepted
  Setaria utowanaea var. ophiticola (Hitchc. & Ekman) W.E. Fox -- accepted
  Setaria utowanaea var. subtransiens (Hitchc. & Ekman) W.E. Fox -- accepted
  Setaria viridis var. breviseta (Döll) Hitchc. -- not accepted
  Sidalcea candida var. glabrata C.L. Hitchc. -- not accepted -- white checkerbloom, white checkermallow
  Sidalcea cusickii ssp. purpurea C.L. Hitchc. -- not accepted
  Sidalcea hickmanii ssp. anomala C.L. Hitchc. -- accepted -- Cuesta Pass checker, Cuesta Pass sidalcea
  Sidalcea hickmanii ssp. parishii (B.L. Rob.) C.L. Hitchc. -- accepted -- Parish's checkerbloom
  Sidalcea hickmanii ssp. viridis C.L. Hitchc. -- accepted -- Marin checkerbloom, Marin checkermallow
  Sidalcea hickmannii var. anomala C.L. Hitchc. -- not accepted
  Sidalcea hickmannii var. parishii (B.L. Rob.) C.L. Hitchc. -- not accepted
  Sidalcea hickmannii var. viridis C.L. Hitchc. -- not accepted
  Sidalcea hirtipes C.L. Hitchc. -- accepted -- bristlystem checkerbloom
  Sidalcea malvaeflora ssp. patula C.L. Hitchc. -- not accepted
  Sidalcea malviflora ssp. asprella (Greene) C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. californica (Nutt. ex Torr. & A. Gray) C.L. Hitchc. -- accepted -- California checkerbloom
  Sidalcea malviflora ssp. celata (Jeps.) C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. dolosa C.L. Hitchc. -- accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. elegans (Greene) C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. laciniata C.L. Hitchc. -- accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. laciniata var. laciniata C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. laciniata var. sancta C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. nana (Jeps.) C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. patula C.L. Hitchc. -- accepted -- Siskiyou checkerbloom
  Sidalcea malviflora ssp. purpurea C.L. Hitchc. -- accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. sparsifolia C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. sparsifolia var. hirsuta C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. sparsifolia var. sparsifolia C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. sparsifolia var. stellata C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. sparsifolia var. uliginosa C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora ssp. virgata (Howell) C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora var. hirsuta C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora var. laciniata C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora var. sancta C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora var. sparsifolia C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora var. stellata C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea malviflora var. uliginosa C.L. Hitchc. -- not accepted -- dwarf checkerbloom
  Sidalcea neomexicana ssp. crenulata (A. Nelson) C.L. Hitchc. -- not accepted -- New Mexico checkermallow, salt spring checkerbloom
  Sidalcea neomexicana ssp. thurberi (B.L. Rob.) C.L. Hitchc. -- not accepted -- Rocky Mountain checker-mallow, Thurber's checkerbloom, Thurber's checkermallow
  Sidalcea neomexicana var. crenulata (A. Nelson) C.L. Hitchc. -- not accepted
  Sidalcea oregana ssp. eximia (Greene) C.L. Hitchc. -- accepted -- coast checkerbloom
  Sidalcea oregana ssp. hydrophila (A. Heller) C.L. Hitchc. -- accepted -- Oregon checkerbloom, water-loving checker-mallow
  Sidalcea oregana ssp. oregana var. calva C.L. Hitchc. -- not accepted -- Oregon checkerbloom
  Sidalcea oregana ssp. oregana var. maxima (M. Peck) C.L. Hitchc. -- not accepted -- Oregon checkerbloom, Oregon checkermallow
  Sidalcea oregana ssp. oregana var. nevadensis C.L. Hitchc. -- not accepted -- Nevada checkermallow, Oregon checkerbloom
  Sidalcea oregana ssp. oregana var. procera C.L. Hitchc. -- not accepted -- Oregon checkerbloom, Oregon checkermallow
  Sidalcea oregana ssp. spicata (Regel) C.L. Hitchc. -- accepted -- Oregon checkerbloom, Oregon checkermallow
  Sidalcea oregana ssp. valida (Greene) C.L. Hitchc. -- accepted -- Kenwood Marsh checker-mallow, Kenwood Marsh checkerbloom
  Sidalcea oregana var. calva C.L. Hitchc. -- not accepted -- Oregon checkerbloom, Wenatchee Mountains checker-mallow
  Sidalcea oregana var. maxima (M. Peck) C.L. Hitchc. -- not accepted -- Oregon checkerbloom
  Sidalcea oregana var. nevadensis C.L. Hitchc. -- not accepted -- Oregon checkerbloom
  Sidalcea oregana var. procera C.L. Hitchc. -- not accepted -- Oregon checkerbloom
  Sidalcea setosa C.L. Hitchc. -- accepted -- bristly-fruited checkerbloom, Edgewood checkerbloom
  Sidalcea setosa ssp. querceta C.L. Hitchc. -- not accepted
  Sidalcea setosa ssp. setosa C.L. Hitchc. -- not accepted -- Edgewood checkermallow
  Sidalcea sparsifolia (C.L. Hitchc.) S.R. Hill -- accepted -- southern checkerbloom
  Silene bernardina ssp. maguirei var. sierrae (C.L. Hitchc. & Maguire) Bocquet -- not accepted
  Silene bernardina var. sierrae (C.L. Hitchc. & Maguire) Bocquet -- not accepted -- Palmer's catchfly
  Silene campanulata ssp. glandulosa C.L. Hitchc. & Maguire -- accepted -- bell catchfly, Red Mountain catchfly
  Silene campanulata ssp. greenei (S. Watson) C.L. Hitchc. & Maguire -- not accepted -- Greene's catchfly
  Silene clokeyi C.L. Hitchc. & Maguire -- not accepted -- Clokey's campion, Clokey's catchfly
  Silene douglasii var. oraria (M. Peck) C.L. Hitchc. & Maguire -- accepted -- Cascade Head catchfly, seabluff catchfly
  Silene douglasii var. villosa C.L. Hitchc. & Maguire -- not accepted
  Silene hookeri ssp. pulverulenta (M. Peck) C.L. Hitchc. & Maguire -- not accepted -- Hooker's silene
  Silene invisa C.L. Hitchc. & Maguire -- accepted -- red fir catchfly
  Silene laciniata ssp. brandegeei C.L. Hitchc. & Maguire -- not accepted
  Silene laciniata ssp. brandegei C.L. Hitchc. & Maguire -- not accepted
  Silene laciniata ssp. greggii (A. Gray) C.L. Hitchc. & Maguire -- accepted -- cardinal catchfly, Gregg's campion
  Silene laciniata ssp. major C.L. Hitchc. & Maguire -- not accepted -- cardinal catchfly
  Silene laciniata ssp. major var. angustifolia C.L. Hitchc. & Maguire -- not accepted -- cardinal catchfly
  Silene laciniata ssp. major var. latifolia C.L. Hitchc. & Maguire -- not accepted -- cardinal catchfly
  Silene laciniata ssp. major var. major (C.L. Hitchc. & Maguire) C.L. Hitchc. & Maguire -- not accepted -- cardinal catchfly
  Silene laciniata var. angustifolia C.L. Hitchc. & Maguire -- not accepted -- cardinal catchfly
  Silene laciniata var. latifolia C.L. Hitchc. & Maguire -- not accepted -- cardinal catchfly
  Silene menziesii ssp. dorrii (Kellogg) C.L. Hitchc. & Maguire -- not accepted -- Dorr's campion, Menzies' campion
  Silene menziesii ssp. menziesii var. viscosa (Greene) C.L. Hitchc. & Maguire -- not accepted
  Silene menziesii var. viscosa (Greene) C.L. Hitchc. & Maguire -- not accepted -- Menzies' campion
  Silene montana ssp. bernardina (S. Watson) C.L. Hitchc. & Maguire -- not accepted
  Silene montana var. sierrae C.L. Hitchc. & Maguire -- not accepted
  Silene nuda (S. Watson) C.L. Hitchc. & Maguire -- accepted -- barestem campion, western fringed catchfly
  Silene nuda ssp. insectivora (L.F. Hend.) C.L. Hitchc. & Maguire -- not accepted -- carnivorous silene, insecteating campion
  Silene nuda ssp. nuda (S. Watson) C.L. Hitchc. & Maguire -- not accepted -- western fringed campion, western fringed catchfly
  Silene occidentalis ssp. longistipitata C.L. Hitchc. & Maguire -- not accepted -- Butte County catchfly, western catchfly
  Silene parishii var. latifolia C.L. Hitchc. & Maguire -- not accepted -- Parish's catchfly
  Silene parishii var. viscida C.L. Hitchc. & Maguire -- not accepted -- Parish's catchfly
  Silene parryi (S. Watson) C.L. Hitchc. & Maguire -- accepted -- Parry's silene
  Silene petersonii var. minor C.L. Hitchc. & Maguire -- not accepted -- plateau catchfly, Red Canyon catchfly
  Silene plankii C.L. Hitchc. & Maguire -- accepted -- Plank's catchfly
  Silene repens ssp. australis C.L. Hitchc. & Maguire -- not accepted -- pink campion
  Silene repens ssp. purpurata (Greene) C.L. Hitchc. & Maguire -- not accepted -- pink campion
  Silene repens var. australis (C.L. Hitchc. & Maguire) C.L. Hitchc. -- not accepted
  Silene scaposa var. lobata C.L. Hitchc. & Maguire -- not accepted -- Lost River campion, Lost River silene
  Silene scouleri ssp. grandis (Eastw.) C.L. Hitchc. & Maguire -- not accepted
  Silene scouleri ssp. hallii (S. Watson) C.L. Hitchc. & Maguire -- accepted -- simple campion
  Silene scouleri ssp. pringlei (S. Watson) C.L. Hitchc. & Maguire -- accepted -- Pringle's catchfly, simple campion
  Silene scouleri ssp. pringlei var. concolor (Greene) C.L. Hitchc. & Maguire -- not accepted
  Silene scouleri ssp. pringlei var. eglandulosa C.L. Hitchc. & Maguire -- not accepted
  Silene scouleri ssp. pringlei var. grisea C.L. Hitchc. & Maguire -- not accepted
  Silene scouleri ssp. pringlei var. leptophylla C.L. Hitchc. & Maguire -- not accepted
  Silene scouleri ssp. pringlei var. pringlei (S. Watson) C.L. Hitchc. & Maguire ex Kartesz & Gandhi -- not accepted
  Silene scouleri ssp. scouleri var. pacifica (Eastw.) C.L. Hitchc. -- not accepted -- simple campion
  Silene scouleri var. concolor (Greene) C.L. Hitchc. & Maguire -- not accepted -- simple campion
  Silene scouleri var. eglandulosa C.L. Hitchc. & Maguire -- not accepted -- simple campion, simple catchfly
  Silene scouleri var. grisea C.L. Hitchc. & Maguire -- not accepted -- simple campion
  Silene scouleri var. leptophylla C.L. Hitchc. & Maguire -- not accepted -- simple campion
  Silene scouleri var. pacifica (Eastw.) C.L. Hitchc. -- not accepted -- simple campion
  Silene scouleri var. pringlei (S. Watson) C.L. Hitchc. & Maguire ex Kartesz & Gandhi -- not accepted -- simple campion
  Silene verecunda ssp. andersonii (Clokey) C.L. Hitchc. & Maguire -- not accepted -- Anderson's campion, San Francisco campion
  Silene verecunda ssp. platyota (S. Watson) C.L. Hitchc. & Maguire -- not accepted -- San Francisco campion
  Silene verecunda ssp. platyota var. eglandulosa C.L. Hitchc. & Maguire -- not accepted -- San Francisco campion
  Silene verecunda var. eglandulosa C.L. Hitchc. & Maguire -- not accepted -- San Francisco campion
  Sitanion hystrix var. brevifolium (J.G. Sm.) C.L. Hitchc. -- not accepted
  Sitanion hystrix var. hordeoides (Suksd.) C.L. Hitchc. -- not accepted
  Sorbus scopulina var. cascadensis (G.N. Jones) C.L. Hitchc. -- not accepted -- Cascade mountain-ash
  Sorbus sitchensis var. grayi (Wenzig) C.L. Hitchc. -- accepted -- western mountain-ash
  Sorengia anceps ssp. rhizomata (Hitchc. & Chase) Zuloaga & Morrrone -- not accepted
  Sorengia petersonii (Hitchc. & Ekman) Zuloaga & Morrone -- not accepted
  Sorghastrum agrostoides (Speg.) Hitchc. -- not accepted
  Sorghastrum francavillanum (E. Fourn.) Hitchc. -- not accepted
  Sorghastrum liebmannianum Hitchc. -- not accepted
  Sorghastrum minarum (Nees) Hitchc. -- accepted
  Sorghastrum parviflorum Hitchc. & Chase -- not accepted
  Sorghastrum parviflorum (Desv. ex Ham.) Hitchc. & Chase -- not accepted -- smallflower Indiangrass
  Sorghastrum setosum (Griseb.) Hitchc. -- accepted -- sandysoil Indiangrass
  Sorghum bicolor var. sudanense (Piper) Hitchc. -- not accepted
  Sorghum propinquum (Kunth) Hitchc. -- accepted -- sorghum
  Sorghum vulgare var. drummondii (Nees ex Steud.) Hitchc. -- not accepted
  Sorghum vulgare var. sudanense (Piper) Hitchc. -- not accepted
  Spartina cynosuroides var. michauxiana (Hitchc.) St.-Yves -- not accepted
  Spartina michauxiana Hitchc. -- not accepted
  Spartina patens var. caespitosa (A.A. Eaton) Hitchc. -- not accepted
  Spartina patens var. juncea (Michx.) Hitchc. -- not accepted
  Spartina spartinae (Trin.) Merr. ex Hitchc. -- accepted -- gulf cordgrass
  Sphenopholis longiflora (Vasey ex L.H. Dewey) Hitchc. -- accepted -- Texas wedgescale
  Sphenopholis pensylvanica (L.) Hitchc. -- accepted -- swamp wedgescale
  Spiraea betulifolia var. lucida (Douglas ex Greene) C.L. Hitchc. -- accepted -- shinyleaf spirea
  Spiraea densiflora var. splendens (Baumann ex K. Koch) C.L. Hitchc. -- not accepted
  Spiraea douglasii var. roseata (Rydb.) C.L. Hitchc. -- not accepted
  Sporobolus asper var. pilosus (Vasey) Hitchc. -- not accepted
  Sporobolus berterianus (Trin.) Hitchc. & Chase -- not accepted
  Sporobolus berteroanus (Trin.) Hitchc. & Chase -- not accepted
  Sporobolus clandestinus (Biehler) Hitchc. -- accepted -- rough dropseed
  Sporobolus contractus Hitchc. -- accepted -- spike dropseed
  Sporobolus cubensis Hitchc. -- accepted -- Cuban dropseed
  Sporobolus erectus Hitchc. -- accepted
  Sporobolus macer (Trin.) Hitchc. -- not accepted
  Sporobolus macrus Hitchc. -- not accepted
  Sporobolus microspermus (Lag.) Hitchc. -- not accepted -- dropseed
  Sporobolus minutissimus (Steud.) Hitchc. -- not accepted
  Sporobolus muelleri (E. Fourn.) Hitchc. -- not accepted
  Sporobolus muralis (Raddi) Hitchc. & Chase -- not accepted
  Sporobolus poiretii (Roem. & Schult.) Hitchc. -- not accepted
  Sporobolus pyramidatus (Lam.) Hitchc. -- accepted -- whorled dropseed
  Sporobolus tharpii Hitchc. -- not accepted -- Tharp's dropseed
  Sporobolus trichodes Hitchc. -- accepted
  Sporobolus virginicus var. littoralis (Lam.) Hitchc. -- not accepted
  Steinchisma cuprea (Hitchc. & Chase) W.V. Br. -- accepted
  Steironema quadriflorum (Sims) Hitchc. -- not accepted
  Stellaria longipes var. altocaulis (Hultén) C.L. Hitchc. -- not accepted
  Stellaria simcoei (Howell) C.L. Hitchc. -- not accepted
  Stipa angustifolia Hitchc. -- not accepted
  Stipa argentea Hitchc. -- not accepted
  Stipa brachyphylla Hitchc. -- not accepted
  Stipa breviculmis Hitchc. -- not accepted
  Stipa breviseta (Hitchc.) Martic. & Quezada -- not accepted
  Stipa capilliseta Hitchc. -- not accepted
  Stipa columbiana var. nelsonii (Scribn.) Hitchc. -- not accepted
  Stipa constricta Hitchc. -- not accepted
  Stipa coronata ssp. parishii (Vasey) Hitchc. -- not accepted
  Stipa coronata var. depauperata (M.E. Jones) Hitchc. -- not accepted
  Stipa coronata var. parishii (Vasey) Hitchc. -- not accepted
  Stipa curtiseta (Hitchc.) Barkworth -- not accepted
  Stipa curviseta Hitchc. -- not accepted
  Stipa dasycarpa Hitchc. -- not accepted
  Stipa disticha Hitchc. -- not accepted
  Stipa featherstonei Hitchc. -- not accepted
  Stipa gilliesii Hitchc. -- not accepted
  Stipa hirtifolia Hitchc. -- not accepted
  Stipa holwayii Hitchc. -- not accepted
  Stipa karstenii Hitchc. -- not accepted
  Stipa leiantha Hitchc. -- not accepted
  Stipa lenta Hitchc. -- not accepted
  Stipa lepida Hitchc. -- not accepted
  Stipa lepida var. andersonii (Vasey) Hitchc. -- not accepted
  Stipa lepida var. lepida Hitchc. -- not accepted -- foothill needlegrass
  Stipa leptostachya var. capilliseta (Hitchc.) Parodi -- not accepted
  Stipa macbridei Hitchc. -- not accepted
  Stipa mexicana Hitchc. -- not accepted
  Stipa milleana Hitchc. -- not accepted
  Stipa nardoides (Phil.) Hack. ex Hitchc. -- not accepted
  Stipa obtusa (Nees & Meyen) Hitchc. -- not accepted
  Stipa occidentalis var. californica (Merr. & Burtt Davy) C.L. Hitchc. -- not accepted
  Stipa occidentalis var. minor (Vasey) C.L. Hitchc. -- not accepted
  Stipa occidentalis var. nelsonii (Scribn.) C.L. Hitchc. -- not accepted
  Stipa paniculata Hitchc. -- not accepted
  Stipa papillosa (Hack.) Hitchc. -- not accepted
  Stipa peruviana Hitchc. -- not accepted
  Stipa pittieri Hitchc. -- not accepted
  Stipa pulchra Hitchc. -- not accepted
  Stipa rigidiseta (Pilg.) Hitchc. -- not accepted
  Stipa rosea Hitchc. -- not accepted
  Stipa saxicola Hitchc. -- not accepted
  Stipa smithii Hitchc. -- not accepted
  Stipa spartea ssp. curtiseta Hitchc. -- not accepted
  Stipa spartea var. curtiseta Hitchc. -- not accepted
  Stipa violacea Hitchc. -- not accepted
  Sucrea sampaiana (Hitchc.) Soderstr. -- accepted
  Swallenochloa subtessellata (Hitchc.) McClure -- not accepted
  Syntherisma aequatoriensis Hitchc. -- not accepted
  Syntherisma aequiglumis (Hack. & Arechav.) Hitchc. -- not accepted
  Syntherisma argillacea Hitchc. & Chase -- not accepted
  Syntherisma argyrostachya (Steud.) Hitchc. & Chase -- not accepted
  Syntherisma chinense (Nees) Hitchc. -- not accepted
  Syntherisma chinensis (Nees) Hitchc. -- not accepted
  Syntherisma curvinervis (Hack.) Hitchc. & Chase -- not accepted
  Syntherisma cuyabensis (Trin.) Hitchc. -- not accepted
  Syntherisma digitata (Sw.) Hitchc. -- not accepted
  Syntherisma floridana Hitchc. -- not accepted
  Syntherisma leiantha (Hack.) Hitchc. -- not accepted
  Syntherisma malacophylla Hitchc. -- not accepted
  Syntherisma microbachne (J. Presl) Hitchc. -- not accepted
  Syntherisma pauciflora Hitchc. -- not accepted
  Syntherisma pauciflorum Hitchc. -- not accepted
  Terrellia canadensis var. glaucifolia (Willd.) Lunell ex Hitchc. -- not accepted
  Terrellia virginica var. submutica (Hook.) Lunell ex Hitchc. -- not accepted
  Thlaspi fendleri var. glaucum (A. Nelson) C.L. Hitchc. -- not accepted
  Thlaspi fendleri var. hesperium (Payson) C.L. Hitchc. -- not accepted
  Thlaspi fendleri var. idahoense (Payson) C.L. Hitchc. -- not accepted
  Thrasya robusta Hitchc. & Chase -- not accepted
  Thrasya villosa Hitchc. -- not accepted
  Tofieldia glutinosa ssp. absona C.L. Hitchc. -- not accepted -- Priest Lake tofieldia
  Tofieldia glutinosa ssp. brevistyla C.L. Hitchc. -- not accepted -- sticky tofieldia
  Tofieldia glutinosa ssp. montana C.L. Hitchc. -- not accepted -- sticky tofieldia, tall tofieldia
  Tofieldia glutinosa ssp. occidentalis (S. Watson) C.L. Hitchc. -- not accepted -- western tofieldia
  Tofieldia glutinosa var. absona (C.L. Hitchc.) R.J. Davis -- not accepted
  Tofieldia glutinosa var. brevistyla (C.L. Hitchc.) C.L. Hitchc. -- not accepted
  Tofieldia glutinosa var. montana (C.L. Hitchc.) R.J. Davis -- not accepted
  Tofieldia glutinosa var. occidentalis (S. Watson) C.L. Hitchc. -- not accepted
  Torresia alpina (Sw. ex Willd.) Hitchc. -- not accepted
  Torresia macrophylla (Thurb. ex Bol.) Hitchc. -- not accepted
  Torresia mexicana Hitchc. -- not accepted
  Torresia odorata (L.) Hitchc. -- not accepted
  Torreyochloa erecta (Hitchc.) G.L. Church -- accepted -- spiked false mannagrass
  Torreyochloa fernaldii (Hitchc.) G.L. Church -- not accepted
  Torreyochloa otisii (Hitchc.) G.L. Church -- not accepted
  Torreyochloa pallida var. fernaldii (Hitchc.) Dore -- accepted -- Fernald's false mannagrass
  Trachypogon filifolius (Hack.) Hitchc. -- not accepted
  Trautvetteria caroliniensis var. occidentalis (A. Gray) C.L. Hitchc. -- not accepted -- western bugbane
  Triantha occidentalis ssp. brevistyla (C.L. Hitchc.) Packer -- accepted -- sticky tofieldia
  Triantha occidentalis ssp. montana (C.L. Hitchc.) Packer -- accepted -- sticky tofieldia
  Trichachne laxa (Rchb.) Hitchc. -- not accepted
  Trichachne pittieri (Hack.) Hitchc. -- not accepted
  Tricholaena repens (Willd.) Hitchc. -- not accepted
  Tridens avenaceus (Kunth) Hitchc. -- not accepted
  Tridens avenaceus var. avenaceus (Kunth) Hitchc. -- not accepted
  Tridens flavus (L.) Hitchc. -- accepted -- purpletop, purpletop tridens
  Tridens flavus var. flavus (L.) Hitchc. -- accepted -- purpletop tridens
  Tridens pilosus (Buckley) Hitchc. -- not accepted
  Tridens pulchellus (Kunth) Hitchc. -- not accepted
  Trifolium longipes var. multiovulatum (L.F. Hend.) C.L. Hitchc. -- not accepted
  Trifolium longipes var. pedunculatum (Rydb.) C.L. Hitchc. -- not accepted
  Trifolium variegatum var. rostratum (Greene) C.L. Hitchc. -- not accepted
  Triniochloa Hitchc. -- accepted
  Triniochloa laxa Hitchc. -- accepted
  Triniochloa micrantha (Scribn.) Hitchc. -- accepted
  Triniochloa stipoides (Kunth) Hitchc. -- accepted
  Triodia buckleyana (Vasey ex L.H. Dewey) Vasey ex Hitchc. -- not accepted
  Triodia flaccida (Döll) Hitchc. -- not accepted
  Triodia flava (L.) Hitchc. -- not accepted
  Triodia multinervosa (Vasey) Hitchc. -- not accepted
  Tripsacum dactyloides ssp. hispidum Hitchc. -- not accepted
  Tripsacum dactyloides var. hispidum (Hitchc.) de Wet & J.R. Harlan -- accepted
  Tripsacum latifolium Hitchc. -- accepted -- wideleaf gamagrass
  Trisetum bulbosum Hitchc. -- accepted
  Trisetum evolutum (E. Fourn.) Hitchc. -- not accepted
  Trisetum fournieranum Hitchc. -- not accepted
  Trisetum irazuense (Kuntze) Hitchc. -- accepted
  Trisetum latifolium Hitchc. -- accepted -- broadleaf false oat
  Trisetum macbridei Hitchc. -- accepted
  Trisetum melicoides var. majus (A. Gray) Hitchc. -- not accepted
  Trisetum orthochaetum Hitchc. -- accepted -- hybrid false oat
  Trisetum palmeri Hitchc. -- accepted
  Trisetum pringlei (Scribn. ex Beal) Hitchc. -- accepted
  Trisetum scabriflorum Hitchc. -- not accepted
  Trisetum spicatum var. congdonii (Scribn. & Merr.) Hitchc. -- not accepted
  Trisetum tonduzii Hitchc. -- accepted
  Tristachya angustifolia Hitchc. -- accepted
  Uniola condensata Hitchc. -- accepted
  Urochloa meziana (Hitchc.) Morrone & Zuloaga -- accepted
  Urtica dioica var. californica (Greene) C.L. Hitchc. -- not accepted
  Urtica dioica var. gracilis (Aiton) C.L. Hitchc. -- not accepted
  Urtica dioica var. holosericea (Nutt.) C.L. Hitchc. -- not accepted
  Urtica dioica var. lyallii (S. Watson) C.L. Hitchc. -- not accepted
  Valota eggersii (Hack.) Hitchc. & Chase -- not accepted
  Valota laxa (Rchb.) Hitchc. & Chase -- not accepted
  Vaseyochloa Hitchc. -- accepted -- Texasgrass
  Vaseyochloa multinervosa (Vasey) Hitchc. -- accepted -- Texasgrass
  Veratrum californicum var. caudatum (A. Heller) C.L. Hitchc. -- accepted -- Cascade false hellebore
  Viola adunca var. cascadensis (M.S. Baker) C.L. Hitchc. -- not accepted
  Viola adunca var. uncinulata (Greene) C.L. Hitchc. -- not accepted
  Viola canadensis var. rugulosa (Greene) C.L. Hitchc. -- accepted -- Canadian white violet, creepingroot violet
  Viola macloskeyi var. pallens (Banks ex DC.) C.L. Hitchc. -- not accepted
  Viola nephrophylla var. cognata (Greene) C.L. Hitchc. -- not accepted
  Viola nuttallii var. bakeri (Greene) C.L. Hitchc. -- not accepted
  Vulpia tracyi (Hitchc.) Henrard -- not accepted
  Wedelia trilobata (L.) Hitchc. -- not accepted -- Bay Biscayne creeping oxeye, wedelia
  Willbleibia texana (Hitchc.) Herter -- not accepted
  Willkommia texana Hitchc. -- accepted -- Texas wilkommia, Texas willkommia
  Willkommia texana var. texana Hitchc. -- accepted
  X Agroelymus hirtiflorus (Hitchc.) Bowden -- not accepted
  X Elyleymus hirtiflorus (Hitchc.) Barkworth -- accepted -- Canadian wildrye, Wyoming wildrye
  Zea gracillima (Körn. ex Hitchc.) hort. ex Vilmorin -- not accepted
  Zea mays var. gracillima Körn. ex Hitchc. -- not accepted
  Zea minima (Körn. ex Hitchc.) hort. ex Vilmorin -- not accepted
  Zea perennis (Hitchc.) Reeves & Mangelsd. -- accepted -- perennial teosinte
  Zea perennis ssp. perennis (Hitchc.) Reeves & Mangelsd. -- not accepted
  Zeugites capillaris (Hitchc.) Swallen -- accepted
  Zizania aquatica ssp. angustifolia (Hitchc.) Tzvelev -- not accepted
  Zizania aquatica var. angustifolia Hitchc. -- not accepted
  Zizania texana Hitchc. -- accepted -- Texas wild-rice, Texas wildrice
   

A gray bar