The new genus Bambusiporia and a new species of Etheirodon in Steccherinaceae (Polyporales, Basidiomycota) from China.

Steccherinaceae is a speciose family of wood-inhabiting fungi containing various hymenophore configurations. Phylogenetic and morphological analyses of Steccherinaceae were carried out. Phylogenies were reconstructed using four genetic loci, including ITS, nLSU, tef1, and mtSSU. A new poroid genus, Bambusiporia, growing on dead bamboo from Yunnan Province in southwest China and typified by Bambusiporia nivea, is illustrated and described. It is characterized by resupinate basidiomata with a white pore surface when fresh, a monomitic hyphal system bearing clamp connections on generative hyphae, and ellipsoid, slightly thick-walled basidiospores. In addition, a new species in Etheirodon, E. lilacinum, is described, and it is characterized by resupinate to effused-reflexed basidiomata with a lilac hydnoid hymenophore when fresh; a dimitic hyphal system bearing clamp connections on generative hyphae; encrusted contextual generative hyphae; the absence of encrusted cystidia; and ellipsoid to broadly ellipsoid basidiospores measuring 4-4.5 × 3-3.8 µm. Moreover, the evolutionary timing of the main clades in Steccherinaceae was revealed based on conserved regions of two nuclear ribosomal genetic markers (ITS + nLSU). The ancestor of Steccherinaceae evolved during the early Cretaceous at 109.27 Myr [95% highest posterior density (HPD) of 81.91-141.87 Mya]. The initial diversification of the Bambusiporia clade occurred during the late Cretaceous with a mean crown age of 83.23 Myr [95% highest posterior density (HPD) of 56.74-112.09 Myr], earlier than other genera in Steccherinaceae. The Etheirodon clade emerged with a mean stem age of 51.98 Myr [95% highest posterior density (HPD) of 34.49-73.82 Myr] and a mean crown age of 19.56 Myr [95% highest posterior density (HPD) of 12.02-29.35 Myr].