Abstract
Sanghuangporus toxicodendri (Hymenochaetales) is described as new based on collections made from Shennongjia Forestry District, Hubei Province, China. All studied basidiocarps grew on living trunks of Toxicodendron sp. This new species is characterized by having perennial, effused-reflexed to pileate basidiocarps; pore surface brownish yellow or yellowish brown, pores 7-9 per mm; context 1-5 mm thick or almost invisible; setae ventricose, dark brown, 26-42 × 7-10 μm; basidia 4-sterigmate or occasionally 2-sterigmate; basidiospores broadly ellipsoid, smooth, brownish yellow, slightly thick-walled, mostly 3.5-4 × 2.8-3 μm. Maximum likelihood and Bayesian inference phylogenies inferred from internal transcribed spacer (ITS) region of rDNA indicated that Sanghuangporus spp. formed a monophyletic clade and resolved as a sister to Tropicoporus spp., and six strains of S. toxicodendri formed a monophyletic group which is sister to S. quercicola. An identification key to known species of Sanghuangporus is provided.