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.