Achyrophorus brasiliensis Gardner accepted as Hypochaeris lutea (Vell.) Britton (original description)
Baccharis alpestris Gardner (original description)
Baccharis ciliata Gardner (original description)
Baccharis depauperata Gardner accepted as Baccharis serrulata (Lam.) Pers. (original description)
Baccharis laxa Gardner accepted as Baccharis trinervis Pers. (original description)
Baccharis pyramidalis Gardner (original description)
Baccharis stylosa Gardner (original description)
Baccharis vaccinioides Gardner accepted as Baccharis pseudovaccinioides Malag. (original description)
Bidens speciosa Gardner accepted as Bidens segetum Mart. ex Colla (original description)
Conyza rivularis Gardner accepted as Podocoma rivularis (Gardner) G.L.Nesom accepted as Exostigma rivulare (Gardner) Sancho (original description)
Erigeron alpestris Gardner accepted as Leptostelma maximum D.Don (original description)
Erigeron palustris Gardner accepted as Leptostelma maximum D.Don (original description)
Fitchia Hook.f. (original description)
Fitchia nutans Hook.f. (original description)
Flotovia leptacantha Gardner accepted as Dasyphyllum leptacanthum (Gardner) Cabrera (original description)
Flotovia quinquenervis Gardner accepted as Dasyphyllum brasiliense (Spreng.) Cabrera (original description)
Leucopodum Gardner accepted as Chevreulia Cass. (original description)
Leucopodum campestre Gardner accepted as Chevreulia acuminata Less. (original description)
Mikania conferta Gardner (original description)
Pluchea organensis Gardner accepted as Pluchea oblongifolia DC. (original description)
Senecio cuneifolius Gardner accepted as Graphistylis cuneifolia (Gardner) B.Nord. (original description)
Stevia organensis Gardner (original description)
Vernonia decumbens Gardner accepted as Lepidaploa decumbens (Gardner) H.Rob. (original description)
Vernonia densiflora Gardner (original description)
Vernonia hilariana Gardner accepted as Vernonanthura petiolaris (DC.) H.Rob. (original description)
Vernonia miersiana Gardner accepted as Lepidaploa salzmannii (DC.) H.Rob. (original description)
Vernonia paludosa Gardner accepted as Vernonanthura paludosa (Gardner) H.Rob. (original description)
Vernonia rupestris Gardner accepted as Cololobus rupestris (Gardner) H.Rob. (original description)
Wedelia scandens Gardner (original description)