Species of Hymenochaete (Hymenochaetales, Basidiomycota) on bamboos from East Asia, with descriptions of two new species

Six species of Hymenochaete are found on bamboos in East Asia. Among them, H. bambusicola and H. orientalis are described and illustrated as new to science. Hymenochaete bambusicola is found exclusively on dead bamboos in northern Thailand and southwestern China, and characterized by the presence of dendrohyphidia and skeletal hyphae. It is phylogenetically and morphologically closely related to H. innexa, H. koeljalgii and H. tropica. Hymenochaete orientalis is found on bamboos in Taiwan and on angiosperm branches in southern China. It is distinguished by the absence of a hyphal layer and by having relatively large, oblong-ellipsoid to cylindrical basidiospores. Hymenochaete orientalis is morphologically similar to H. longispora and H. cinnamomea, and forms a distinct lineage close to H. cinnamomea in the ITS+nrLSU based phylogenetic analyses. An identification key to the six species on bamboos is given.