XVI International Botanical Congess

Bahianthus R. Hing & H. Rob. And Morithamnus R. King & H. Rob. are two endemic genera from Bahia (Brazil), belonging to the subtribe Gyptidinae, tribe Eupatorieae (Asteraceae). King & Robinson(1987) consider that these two genera are closely related. Bahianthus viscosus (Sprengel) R. King * H. Rob. and Morithamnus crassus R. King, H. Rob. & G. Barroso, the first species described in these genera show very pronunced morphological differences. However, the morphologic characters of M. ganophyllus (Mattf.) R King & H. Rob. are ambiguous, and its inclusion in the genus Morithamnus was called into question by the authors of the proposal themselves. In this poster we present a taxonomic study of the species of these two genera and an analysis of their phylogenetic relationships. The results of this study argue for the creation of a new genus, which we name Piatanthus, to include the species Morithamnus ganophyllus.