Taxonomy of Pseudolagarobasidium (Polyporales, Basidiomycota)

Pseudolagarobasidium (Polyporales, Basidiomycota) is a small, monophyletic genus of crustose, wood-inhabiting fungi with spines and a saprobic, endophytic, or parasitic habit. Seven species are accepted in the genus including two new species, P. belizense from Belize and P. pusillum from Australia. Sequence analysis of the internal transcribed spacer of the ribosomal RNA gene places P. belizense in a monophyletic clade with P. acaciicola and an undescribed foliar endophyte. New combinations proposed include P. modestum for Irpex modestus Berk., P. pronum for Hydnum pronum Berk. & Broome which is an earlier name for P. calcareum, and P. venustum for Radulodon venustus Hjortstam & Ryvarden. Irpex colliculosum Berk. & Broome from Sri Lanka is conspecific with P. subvinosum. Two species, Sistotrema ochroleucum and Radulum concentricum are not accepted in Pseudolagarobasidium. Pseudolagarobasidium is compared with Radulodon and similar genera. A key to the species of Pseudolagarobasidium is provided.