New species in the Gymnopilus junonius group (Basidiomycota: Agaricales)

Mushrooms named Gymnopilus spectabilis and G. junonius have been reported widely in North America on both dead hardwood or dead or living conifers. Based on DNA sequences of the internal transcribed spacer region (ITS) and large ribosomal subunit (LSU), we found that although Gymnopilus junonius (= G. spectabilis s. auct.) is widespread in Europe, South America, and Australia, none of the limited sequences available from North America represent this species. We report five species of this group from North America, including three previously described species, G. luteus, G. subspectabilis, and G. ventricosus, and two new species, Gymnopilus voitkii and Gymnopilus speciosissimus. We recognize a sister species to G. luteus, based on sequences previously reported as G. spectabilis from China, Japan, and the Russian Far East, but, lacking material to describe it as a new species, we give it an informal clade name, /sororiluteus. Another new species in this complex is described from Japan, as Gymnopilus orientispectabilis. Species in this group may be distinguished by their ITS sequences as well as by macro- and micromorphology, substrate, and geography.