Tricholoma sinoacerbum, a bitter species from Guangdong Province of China

• Tricholoma sinoacerbum is characterized by its cream-colored cap and bitter taste.
• It differs from T. acerbum by its weakly incurved pileal margin and shorter spores.
• This species is subtropical habitat in evergreen broad-leaved trees in China.

Tricholoma sinoacerbum, a putatively ectomycorrhizal fungus in association with broad-leaved trees is described and illustrated as a new species from Xiangtoushan, a national nature reserve in Guangdong Province of China. The new species is characterized by its cream-colored or pale yellow pileus, bitter taste, strong smell when being dried, ovoid to ellipsoid basidiospores and an ixo-trichoderm pileipellis. Phylogenetic analysis of the internal transcribed spacer (ITS) of nuclear ribosomal RNA clearly showed that three species, namely T. acerbum, T. japonicum and T. roseoacerbum from different geographical regions, are closely related to T. sinoacerbum, but they are easily distinguished from the new species based on the morphological and genetic evidence. Detailed description, color photos and illustrations of the new species are presented.