Arnica lanulosa Greene accepted as Arnica chamissonis Less. (original description)
Arnica parviflora Greene accepted as Arnica cordifolia Hook. (original description)
Arnica silvatica Greene accepted as Arnica mollis Hook. (original description)
Artemisia bakeri Greene accepted as Artemisia carruthii Alph.Wood ex Carruth. (original description)
Erigeron simulans Greene accepted as Erigeron concinnus var. concinnus (Hook. & Arn.) Torr. & A.Gray (original description)
Helianthus fascicularis Greene accepted as Helianthus nuttallii subsp. nuttallii Torr. & A.Gray (original description)
Hymenopappus ochroleucus Greene (original description)
Hymenopappus parvulus Greene accepted as Hymenopappus filifolius var. parvulus (Greene) B.L.Turner (original description)
Psilostrophe bakeri Greene (original description)
Senecio contristatus Greene (original description)
Senecio lapathifolius Greene accepted as Senecio crassulus A.Gray (original description)
Senecio pentodontus Greene (original description)
Senecio pyrrhochrous Greene accepted as Packera crocata (Rydb.) W.A.Weber & Á.Löve (original description)
Tetraneuris intermedia Greene accepted as Tetraneuris ivesiana Greene (original description)