XVI International Botanical Congess

A taxonomic revision of Actinoseris was carried out based on intensive field work and study of herbarium specimens. The genus is endemic to central and southern Brazil, with 19 species mostly restricted to highlands, 7 of them new. A cladistic analysis using PAUP based on morphological, anatomical and palinological data showed that a redefinition of the genus is required: the 19 species form a monophyletic group, supported by the habit (herbs to subshrubs) and the uniseriate pappus, including the species formerly placed in Gochnatia sect. Discoseris, and excluding the species hitherto known as Actinoseris corymbosa (Less.) Cabrera, for which a new genus is proposed. As a main conclusion, the traditional distinction of Gochnatia and Actinoseris based on discoid vs. radiate heads is inconsistent, with both states present in the latter.