Agoseris aspera (Rydb.) Rydb. accepted as Agoseris glauca (Pursh) Raf. (original description)
Agoseris nana Rydb. accepted as Agoseris aurantiaca (Hook.) Greene (original description)
Anaphalis lanata (A.Nelson) Rydb. accepted as Anaphalis margaritacea (L.) Benth. & Hook.f. (original description)
Antennaria albescens (E.E.Nelson) Rydb. accepted as Antennaria rosea subsp. pulvinata (Greene) R.J.Bayer (original description)
Antennaria macrocephala (D.C.Eaton) Rydb. accepted as Antennaria dimorpha (Nutt.) Torr. & A.Gray (original description)
Antennaria pumila Greene ex Rydb. (original description)
Arnica granulifera Rydb. accepted as Arnica latifolia Bong. (original description)
Arnica jonesii Rydb. accepted as Arnica gracilis Rydb. (original description)
Arnica puberula Rydb. accepted as Arnica latifolia Bong. (original description)
Aster stricticaulis (Torr. & A.Gray) Rydb. accepted as Symphyotrichum ericoides (L.) G.L.Nesom (original description)
Aster subgriseus Rydb. accepted as Symphyotrichum ascendens (Lindl.) G.L.Nesom (original description)
Asterigeron Rydb. accepted as Erigeron L. (original description)
Asterigeron watsonii (A.Gray) Rydb. accepted as Erigeron watsonii (A.Gray) Cronquist (original description)
Chrysothamnus concolor (A.Nelson) Rydb. accepted as Ericameria nauseosa (Pall. ex Pursh) G.L.Nesom & G.I.Baird (original description)
Chrysothamnus glareosus (M.E.Jones) Rydb. accepted as Ericameria nauseosa var. psilocarpa (S.F.Blake) G.L.Nesom & G.I.Baird (original description)
Chrysothamnus turbinata (M.E.Jones) Rydb. (original description)
Chrysothamnus turbinatus (M.E.Jones) Rydb. accepted as Ericameria nauseosa var. turbinata (M.E.Jones) G.L.Nesom & G.I.Baird (original description)
Cirsium acuatum (Osterh.) Rydb. accepted as Cirsium tracyi (Rydb.) Petr. (original description)
Cirsium araneans Rydb. accepted as Cirsium clavatum var. osterhoutii (Rydb.) D.J.Keil (original description)
Cirsium bipinnatum (Eastw.) Rydb. accepted as Cirsium calcareum (M.E.Jones) Wooton & Standl. (original description)
Cirsium butleri (Rydb.) Rydb. accepted as Cirsium scariosum var. scariosum Nutt. (original description)
Cirsium canovirens (Rydb.) Rydb. accepted as Cirsium cymosum var. canovirens (Rydb.) D.J.Keil (original description)
Cirsium clavatum (M.E.Jones) Rydb. accepted as Cirsium clavatum (M.E.Jones) Petr. (original description)
Cirsium diffusum (Eastw.) Rydb. accepted as Cirsium calcareum (M.E.Jones) Wooton & Standl. (original description)
Cirsium engelmannii Rydb. (original description)
Cirsium floccosum (Rydb.) Rydb. accepted as Cirsium tracyi (Rydb.) Petr. (original description)
Cirsium hesperium (Eastw.) Rydb. accepted as Cirsium eatonii var. hesperium (Eastw.) D.J.Keil (original description)
Cirsium humboldtense Rydb. accepted as Cirsium neomexicanum A.Gray (original description)
Cirsium kelseyi (Rydb.) Rydb. accepted as Cirsium scariosum var. coloradense (Rydb.) D.J.Keil (original description)
Cirsium lacerum (Rydb.) Rydb. accepted as Cirsium scariosum var. scariosum Nutt. (original description)
Cirsium lactucinum Rydb. accepted as Cirsium rydbergii Petr. (original description)
Cirsium laterifolium (Osterh.) Rydb. accepted as Cirsium scariosum var. americanum (A.Gray) D.J.Keil (original description)
Cirsium macounii (Greene) Rydb. accepted as Cirsium edule var. macounii (Greene) D.J.Keil (original description)
Cirsium magnificum (A.Nelson) Rydb. accepted as Cirsium scariosum var. scariosum Nutt. (original description)
Cirsium modestum (Osterh.) Rydb. accepted as Cirsium clavatum var. americanum (A.Gray) D.J.Keil accepted as Cirsium scariosum var. americanum (A.Gray) D.J.Keil (original description)
Cirsium nelsonii (Pammel) Rydb. accepted as Cirsium canescens Nutt. (original description)
Cirsium nidulum (M.E.Jones) Rydb. accepted as Cirsium arizonicum var. arizonicum (A.Gray) Petr. (original description)
Cirsium olivescens (Rydb.) Rydb. accepted as Cirsium scariosum var. coloradense (Rydb.) D.J.Keil (original description)
Cirsium oreophilum (Rydb.) Rydb. accepted as Cirsium oreophilum (Rydb.) K.Schum. (original description)
Cirsium perplexans (Rydb.) Rydb. accepted as Cirsium perplexans (Rydb.) Petr. (original description)
Cirsium polyphyllum (Rydb.) Rydb. accepted as Cirsium eatonii var. murdockii S.L.Welsh (original description)
Cirsium spathulifolium Rydb. accepted as Cirsium scariosum var. americanum (A.Gray) D.J.Keil (original description)
Cirsium subniveum Rydb. (original description)
Cirsium tracyi (Rydb.) Rydb. accepted as Cirsium tracyi (Rydb.) Petr. (original description)
Cirsium tweedyi (Rydb.) Rydb. accepted as Cirsium eatonii var. murdockii S.L.Welsh (original description)
Coleosanthus watsonii (B.L.Rob.) Rydb. accepted as Brickellia watsonii B.L.Rob. (original description)
Ericameria cervina (S.Watson) Rydb. (original description)
Ericameria paniculata (A.Gray) A.Gray ex Rydb. (original description)
Erigeron arenarioides (D.C.Eaton ex A.Gray) A.Gray ex Rydb. (original description)
Erigeron evermannii Rydb. (original description)
Erigeron fruticetorum Rydb. accepted as Erigeron formosissimus Greene (original description)
Erigeron mancus Rydb. (original description)
Erigeron pulvinatus Rydb. accepted as Erigeron compactus S.F.Blake (original description)
Erigeron wyomingius Rydb. (original description)
Eucephalus wasatchensis (M.E.Jones) Rydb. accepted as Herrickia wasatchensis (M.E.Jones) Brouillet (original description)
Grindelia laciniata Rydb. accepted as Grindelia arizonica A.Gray (original description)
Isocoma scopulorum (M.E.Jones) Rydb. accepted as Chrysothamnus scopulorum (M.E.Jones) Urbatsch, R.P.Roberts & Neubig (original description)
Leontodon ammophilus (Greene) Rydb. (original description)
Leontodon angustifolius (Greene) Rydb. (original description)
Leontodon dumetorum (Greene) Rydb. accepted as Taraxacum dumetorum Greene (original description)
Leontodon eriophorum (Rydb.) Rydb. accepted as Taraxacum eriophorum Rydb. (original description)
Leontodon leiospermus (Rydb.) Rydb. (original description)
Leontodon mexicanus Rydb. (original description)
Leontodon monticola Rydb. (original description)
Leontodon rupestris Rydb. (original description)
Leontodon scopulorum (A.Gray) Rydb. accepted as Taraxacum scopulorum (A.Gray) Rydb. (original description)
Oglifa californica (Nutt.) Rydb. accepted as Filago californica Nutt. (original description)
Pleiacanthus (Nutt.) Rydb. (original description)
Pleiacanthus spinosus (Nutt.) Rydb. (original description)
Senecio kuntzei Rydb. (original description)
Senecio pacificus (Greene) Rydb. (original description)
Sideranthus aberrans (A.Nelson) Rydb. accepted as Tonestus aberrans (A.Nelson) G.L.Nesom & D.R.Morgan (original description)
Solidago salebrosa (Piper) Rydb. accepted as Solidago canadensis var. salebrosa (Piper) M.E.Jones (original description)
Townsendia ambigua (A.Gray) Rydb. (original description)
Youngia elegans (Hook.) Rydb. accepted as Askellia elegans (Hook.) W.A.Weber (original description)
Youngia nana (Richardson) Rydb. accepted as Askellia pygmaea (Ledeb.) Sennikov (original description)