Pseudomegasporoporia neriicola gen. et sp nov (Polyporaceae, Basidiomycota) from East Asia

Pseudomegasporoporia is proposed as a new genus in Polyporales based on morphological characters and molecular data. The genus is typified by P. neriicola sp. nov. characterized by an annual growth habit, resupinate basidiocarp with white to cream poroid hymenophore, a dimitic hyphal system with clamp connections and non-dextrinoid and cyanophilous skeletal hyphae, the absence of hyphal pegs and dendrohyphidia, and big, more or less mango-shaped, hyaline, thin- to slightly thick-walled, smooth basidiospores which are negative in Melzer's reagent, but slightly cyanophilous in Cotton Blue, and growing on wood of Nerium. Phylogeny of P. neriicola and its related species was inferred from the combined ITS and nLSU rDNA sequences, and the new species forms a distinct lineage and belongs to the core polyporoid Glade of Polyporales. Pseudomegasporoporia is morphologically similar to Megasporoporia s.1., but the latter genus has dextrinoid skeletal hyphae, the presence of hyphal pegs and dendrohyphidia, and acyanophilous basidiospores.