Agoseris agrestis Osterh. accepted as Agoseris glauca (Pursh) Raf. (original description)
Agoseris arachnoidea Rydb. accepted as Agoseris aurantiaca (Hook.) Greene (original description)
Agoseris pubescens Rydb. accepted as Agoseris glauca (Pursh) Raf. (original description)
Antennaria latisquama Piper accepted as Antennaria dimorpha (Nutt.) Torr. & A.Gray (original description)
Antennaria piperi Rydb. accepted as Antennaria racemosa Hook. (original description)
Arnica tenuis Rydb. accepted as Arnica rydbergii Greene (original description)
Arnica tomentulosa Rydb. accepted as Arnica chamissonis Less. (original description)
Artemisia diversifolia Rydb. accepted as Artemisia ludoviciana subsp. ludoviciana Nutt. (original description)
Artemisia silvicola Osterh. (original description)
Artemisia suksdorfii Piper (original description)
Aster crassulus Rydb. accepted as Symphyotrichum falcatum var. commutatum (Torr. & A.Gray) G.L.Nesom (original description)
Aster exiguus (Fernald) Rydb. accepted as Symphyotrichum ericoides var. ericoides (L.) G.L.Nesom (original description)
Aster mollis Rydb. accepted as Symphyotrichum molle (Rydb.) G.L.Nesom (original description)
Carduus acaulescens (A.Gray) Rydb. accepted as Cirsium scariosum var. americanum (A.Gray) D.J.Keil (original description)
Carduus americanus (A.Gray) Rydb. accepted as Cirsium scariosum var. americanum (A.Gray) D.J.Keil (original description)
Carduus centaureae Rydb. accepted as Cirsium scariosum var. americanum (A.Gray) D.J.Keil (original description)
Carduus erosus Rydb. accepted as Cirsium scariosum var. coloradense (Rydb.) D.J.Keil (original description)
Carduus griseus Rydb. accepted as Cirsium griseum H.Lév. (original description)
Carduus oblanceolatus Rydb. accepted as Cirsium flodmanii (Rydb.) Arthur (original description)
Carduus oreophilus Rydb. accepted as Cirsium eriophilus K.Schum. (original description)
Carduus pulcherrimus Rydb. accepted as Cirsium pulcherrimum (Rydb.) K.Schum. (original description)
Chrysopsis resinolens A.Nelson accepted as Heterotheca fulcrata var. fulcrata (Greene) Shinners (original description)
Chrysopsis resinolens var. ciliata A.Nelson accepted as Heterotheca fulcrata var. fulcrata (Greene) Shinners (original description)
Chrysothamnus filifolius Rydb. accepted as Chrysothamnus greenei (A.Gray) Greene (original description)
Chrysothamnus scoparius Rydb. accepted as Chrysothamnus greenei (A.Gray) Greene (original description)
Crepis glareosa Piper accepted as Crepis modocensis subsp. glareosa (Piper) Babc. & Stebbins (original description)
Crepis glaucella Rydb. accepted as Crepis runcinata subsp. runcinata Torr. & A.Gray (original description)
Erigeron incanescens Rydb. accepted as Erigeron subtrinervis Rydb. ex Porter & Britton (original description)
Erigeron laetevirens Rydb. accepted as Erigeron ochroleucus Nutt. (original description)
Erigeron leibergii Piper (original description)
Erigeron leucotrichus Rydb. accepted as Erigeron speciosus (Lindl.) DC. (original description)
Erigeron viscidus Rydb. accepted as Erigeron formosissimus var. viscidus (Rydb.) Cronquist (original description)
Hieracium scaberrimum Rydb. (original description)
Sonchus andrenarum Cockerell (original description)
Sonchus andrenarum var. osmiarum Cockerell (original description)
Sonchus glandulifera Rydb. (original description)