Favolus is a monophyletic genus of polypores that causes white rot of various woody plants. The genus has a worldwide distribution and is ecologically and economically important. Several taxa have been described or reported from the Neotropics, and F. brasiliensis, described originally from Brazil, is the type species for the genus. Based on molecular investigations, F. brasiliensis is now known to represent a species complex. The species is morphologically and phylogenetically circumscribed and epitypified here, and F. rugulosus is proposed as a new related species. Favolus grammocephalus and Polyporus philippinensis, initially described from Asia, have also recently been recorded from the Neotropics, so these taxa were included in this investigation employing morphological and multigene (mitochondrial, ribosomal, and protein-coding regions) phylogenetic analyses. These latter two species do not occur in the Neotropics, but the misapplied names actually represent three new species: F. pseudogrammocephalus, F. radiatifibrillosus, and F. yanomami. Nine species of Favolus are documented now for the Neotropics. Detailed descriptions of F. brasiliensis and all new taxa are provided, along with comments, illustrations, a map of potential distribution, and a key for neotropical species of Favolus.
Keywords: 4 new taxa; Multigene phylogeny; Polyporales; South America; taxonomy; wood-decaying fungi.