Neoaleurodiscus fujii, a new genus and new species found at the timberline in Japan.

A new genus, Neoaleurodiscus, is proposed as a segregate from Aleurodiscus (Basidiomycota), and the new species, Neoaleurodiscus fujii, is described. It was collected at the timberline of Mount Fuji, Japan. Specimens were found on trunks of Rhododendron sp. Morphological study and phylogenetic analysis based on sequence data derived from LSU nrDNA indicated that Neoaleurodiscus is separate from other segregate genera from Aleurodiscus s.l. Neoaleurodiscus is characterized by having a disciform basidiocarp; microscopically it has moniliform gloeocystidia, absence of acanthophyses, nodose-septate hyphae, hyphidia, and basidiospores, which are amyloid, smooth and +/- thick-walled. Among genera studied Acanthobasidium and Aleurodiscus (s.s.) are most closely related to Neoaleurodiscus, but these genera have warted or spiny basidiospores. Two new combinations, Acanthobasidium penicillatum and Neoaleurodiscus monilifer, are proposed.