Baccharis melanopotamica Speg. (original description)
Baccharis trimera var. viscosissima Speg. accepted as Baccharis triangularis Hauman (original description)
Chiliotrichum diffusum f. angustifolium Speg. (original description)
Chiliotrichum diffusum f. medium Speg. (original description)
Chiliotrichum diffusum f. typicum Speg. (original description)
Erigeron philippii var. elatior Speg. accepted as Erigeron myosotis Pers. (original description)
Erigeron philippii var. humilis Speg. accepted as Erigeron myosotis Pers. (original description)
Haplopappus ameghinoi Speg. (original description)
Haplopappus illini Speg. (original description)
Haplopappus mustersi Speg. (original description)
Haplopappus tehuelches Speg. accepted as Grindelia brachystephana Griseb. (original description)
Psilocarphus globiferus (Bertero ex DC.) Speg. (original description)