<i>Actinocephalus</i> (Körn.) Sano (<i>Paepalanthus</i> sect. <i>Actinocephalus</i>), a new genus of Eriocaulaceae, and other taxonomic and nomenclatural changes involving <i>Paepalanthus</i> Mart.

Abstract Paepalanthus Mart., the largest genus of Eriocaulaceae, has been shown to be polyphyletic by all the phylogenetic analyses performed so far in the family. After intensive and extensive field work and an analysis of various characters in a recent revision of Paepalanthus section Actinocephalus (Körn.) Ruhland, I encountered consistent evidence that this group should be elevated to generic status. This proposal, meant to bring a better comprehension of this group within the family, is supported by the phylogenetic analyses of Giulietti et al. (1995, 2000) that show the group to be monophyletic. Actinocephalus (Körn.) Sano, as proposed here, contains 28 species. The necessary nomenclatural changes are made for the new status, with 28 new combinations proposed, 17 new synonyms, eight lectotypifications, five stati novi and one new name. Actinocephalus (Körn.) Sano is characterized principally by inflorescences composed of capitula in umbels and in having a geographic range restricted to Brazil.