Two new species of Steccherinum (Polyporales, Basidiomycota) from southern China based on morphology and DNA sequence data.

Two new wood-inhabiting fungal species, Steccherinum hirsutum and S. yunnanense spp. nov., are proposed based on a combination of morphological features and molecular evidence. Sequences of internal transcribed spacer and large subunit region of nuculear ribosomal RNA gene of the studied samples were generated, and phylogenetic analyses were performed using maximum likelihood, maximum parsimony and bayesian inference methods. Steccherinum hirsutum is characterized by an annual growth habit, stipitate basidiocarps with scarlet to red, odontioid hymenial surface, a dimitic hyphal system with clamped generative hyphae negative in Melzer's reaction, and acyanophilous basidiospores measuring 2.5-3.5 × 1.5-2.5 µm. Steccherinum yunnanense is distinguished by resupinate basidiomata with odontioid hymenial surface, a dimitic hyphal system with clamped generative hyphae, strongly encrusted cystidia and ellipsoid, hyaline, thin-walled, smooth basidiospores (3.5-4.5 × 2-3.5 µm). The phylogenetic analyses comfirmed that two new species nest in Steccherinum, in the residual polyporoid clade.