A new genus Pseudoaustroboletus (Boletaceae, Boletales) from Asia as inferred from molecular and morphological data

A new genus of Boletaceae, Pseudoaustroboletus, is described to accommodate the phylogenetically isolated species Tylopilus valens inferred by molecular and morphological data. The lineage consisted of T. valens was nested into the Boletaceae clade with high support value using nuclear genes: the large subunit of the nuclear ribosomal RNA (nrLSU), the translation elongation factor 1-alpha (tef1-alpha), and mitochondrial gene: the small subunit (mtSSU) of the ribosomal RNA, based on Maximum Likelihood and Bayesian analyses. Morphologically, Pseudoaustroboletus is distinguished from other boletoid lineages by a combination of morphological characters, including the pale pinkish to light pinkish or greyish pink hymenophore, the distinctly reticulated stipe surface, the smooth basidiospores, the brown to dark yellow-brown pigmented cystidia, and the trichodermial brown to dark brown pigmented pileipellis. Geographically, Pseudoaustroboletus is currently only known from China, Japan, Malaysia and Singapore under forests dominated by Fagaceae plants. The species and its variety macrosporus in this genus are fully documented with taxonomic descriptions and illustrations.