Revision of Kneiffiella with segregation of Egonia gen. nov. (Hymenochaetales, Agaricomycetes): how similar morphology can hide taxonomic diversity in the molecular era

DNA-based phylogenetic inference has shown that many morphological traits, once considered taxonomically relevant, are the result of convergent evolution. In this study, we analyze Kneiffiella, a genus of corticioid and polyporoid wood-inhabiting basidiomycetes in the order Hymenochaetales. A multi-gene-based phylogeny demonstrates that Kneiffiella is polyphyletic, and the new genus Egonia is established for K. cineracea and its relatives, despite their morphological similarity to other Kneiffiella species. Additionally, we present the best resolved phylogram of the Hymenochaetales to date. A revised circumscription of Kneiffiella is presented, as well as an overview of the 29 species accepted in the genus, including 10 new species. Three new species of Egonia are described, and H. subefibulata is placed in synonymy with K. subglobosa. A key to the species of Kneiffiella and Egonia is presented.