Ambrosia media Rydb. (original description)
Anaphalis angustifolia Rydb. accepted as Anaphalis margaritacea (L.) Benth. & Hook.f. (original description)
Antennaria acuta Rydb. (original description)
Arnica caudata Rydb. accepted as Arnica longifolia D.C.Eaton (original description)
Artemisia bourgeauana Rydb. (original description)
Artemisia herriotii Rydb. accepted as Artemisia ludoviciana subsp. ludoviciana Nutt. (original description)
Aster butleri Rydb. accepted as Symphyotrichum subspicatum (Nees) G.L.Nesom (original description)
Aster eriocaulis Rydb. (original description)
Aster franklinianus Rydb. accepted as Symphyotrichum boreale (Torr. & A.Gray) Á.Löve & D.Löve (original description)
Aster junciformis Rydb. accepted as Symphyotrichum boreale (Torr. & A.Gray) Á.Löve & D.Löve (original description)
Aster maccallae Rydb. accepted as Symphyotrichum subspicatum (Nees) G.L.Nesom (original description)
Aster macounii Rydb. accepted as Symphyotrichum ascendens (Lindl.) G.L.Nesom (original description)
Aster masardiensis Rydb. (original description)
Aster mearnsii Rydb. accepted as Symphyotrichum eatonii (A.Gray) G.L.Nesom (original description)
Aster phyllodes Rydb. accepted as Symphyotrichum foliaceum var. canbyi (A.Gray) G.L.Nesom (original description)
Aster roseolus Rydb. (original description)
Aster subcaudatus Rydb. (original description)
Aster subsalignus Rydb. (original description)
Aster umbachii Rydb. (original description)
Aster williamsii Rydb. (original description)
Aster wilsonii Rydb. accepted as Symphyotrichum ciliolatum (Lindl.) Á.Löve & D.Löve (original description)
Bidens shrevei Britton (original description)
Carduus butleri Rydb. accepted as Cirsium scariosum var. scariosum Nutt. (original description)
Carduus lacerus Rydb. accepted as Cirsium scariosum var. scariosum Nutt. (original description)
Carduus olivescens Rydb. accepted as Cirsium scariosum var. coloradense (Rydb.) D.J.Keil (original description)
Carduus polyphyllus Rydb. accepted as Cirsium eatonii var. murdockii S.L.Welsh (original description)
Chaenocephalus propinquus Britton accepted as Verbesina propinqua (Britton) S.F.Blake (original description)
Chrysopsis angustifolia Rydb. accepted as Heterotheca stenophylla var. angustifolia (Rydb.) Semple (original description)
Chrysopsis barbata Rydb. accepted as Heterotheca barbata (Rydb.) Semple (original description)
Chrysopsis butleri Rydb. accepted as Heterotheca villosa var. foliosa (Nutt.) V.L.Harms (original description)
Chrysopsis grandis Rydb. accepted as Heterotheca villosa var. minor (Hook.) Semple (original description)
Chrysothamnus attenuatus (M.E.Jones) Rydb. accepted as Ericameria parryi var. attenuata (M.E.Jones) G.L.Nesom & G.I.Baird (original description)
Chrysothamnus marianus Rydb. accepted as Chrysothamnus viscidiflorus subsp. puberulus (D.C.Eaton) H.M.Hall & Clem. (original description)
Chrysothamnus salicifolius Rydb. accepted as Ericameria nauseosa var. salicifolia (Rydb.) G.L.Nesom & G.I.Baird (original description)
Chrysothamnus stenolepis Rydb. accepted as Chrysothamnus viscidiflorus (Hook.) Nutt. (original description)
Doellingeria pubens (A.Gray) Rydb. accepted as Doellingeria umbellata (Mill.) Nees (original description)
Dubautia waialealae Rock (original description)
Gaillardia mearnsii Rydb. accepted as Gaillardia pinnatifida Torr. (original description)
Gnaphalium williamsii Rydb. accepted as Pseudognaphalium thermale (E.E.Nelson) G.L.Nesom (original description)
Grindelia columbiana (Piper) Rydb. accepted as Grindelia hirsutula Hook. & Arn. (original description)
Grindelia integerrima Rydb. accepted as Grindelia hirsutula Hook. & Arn. (original description)
Gymnolomia ciliata (B.L.Rob. & Greenm.) Rydb. accepted as Heliomeris hispida (A.Gray) Cockerell (original description)
Gymnolomia linearis Rydb. (original description)
Helianthus occidentalis var. illinoensis (Gleason) F.C.Gates (original description)
Hymenoxys greenei (Cockerell) Rydb. (original description)
Hymenoxys macounii (Cockerell) Rydb. (original description)
Machaeranthera angustifolia Rydb. accepted as Dieteria canescens var. canescens (Pursh) Nutt. (original description)
Machaeranthera leptophylla Rydb. accepted as Dieteria canescens var. canescens (Pursh) Nutt. (original description)
Othake macrolepis Rydb. (original description)
Othake sphacelatum (Nutt. ex Torr.) Rydb. accepted as Palafoxia sphacelata (Nutt. ex Torr.) Cory (original description)
Petasites corymbosa Rydb. (original description)
Petasites corymbosus (R.Br.) Rydb. accepted as Petasites frigidus var. frigidus (L.) Fr. (original description)
Picradeniopsis woodhousei (A.Gray) Rydb. (original description)
Platyschkuhria desertorum (M.E.Jones) Rydb. accepted as Platyschkuhria integrifolia (A.Gray) Rydb. (original description)
Platyschkuhria nudicaulis (M.E.Jones) Rydb. (original description)
Saussurea densa (Hook.) Rydb. accepted as Saussurea nuda Ledeb. (original description)
Saussurea remotiflora (Hook.) Rydb. (original description)
Saussurea remotifolia (Hook.) Rydb. (original description)
Senecio ambrosioides Rydb. accepted as Senecio eremophilus var. kingii (Rydb.) Greenm. (original description)
Senecio kingii Rydb. accepted as Senecio eremophilus var. kingii (Rydb.) Greenm. (original description)
Senecio leonardii Rydb. accepted as Packera streptanthifolia (Greene) W.A.Weber & Á.Löve (original description)
Senecio tweedyi Rydb. accepted as Packera paupercula (Michx.) Á.Löve & D.Löve (original description)
Solidago garrettii Rydb. accepted as Solidago velutina subsp. sparsiflora (A.Gray) Semple accepted as Solidago velutina DC. (original description)
Solidago glaucophylla Rydb. accepted as Solidago missouriensis Nutt. (original description)
Solidago nivea Rydb. accepted as Solidago nana Nutt. (original description)
Tetradymia longispina (M.E.Jones) Rydb. accepted as Tetradymia axillaris var. longispina (M.E.Jones) Strother (original description)
Tetraneuris septentrionalis Rydb. accepted as Tetraneuris acaulis var. acaulis (Pursh) Greene (original description)
Unamia alba (Nutt.) Rydb. accepted as Solidago ptarmicoides (Torr. & A.Gray) B.Boivin (original description)
Unamia lutescens (Lindl. ex DC.) Rydb. accepted as Solidago lutescens (Lindl. ex DC.) B.Boivin (original description)
Villanova dissecta (A.Gray) Rydb. accepted as Bahia dissecta (A.Gray) Britton accepted as Hymenothrix dissecta (A.Gray) B.G.Baldwin (original description)
Xylorhiza lanceolata Rydb. accepted as Xylorhiza tortifolia var. tortifolia (Torr. & A.Gray) Greene (original description)