A new species of Arrhenia (Agaricales, Hygrophoraceae) from Guizhou Province, China

Arrhenia nivea is a new bryophilous species of Arrhenia from a valley in southwestern China'a subtropical monsoon humid climate zone.The species is characterized by pure white basidiomata with an irregularly discoid to cupulate 1.5-4.5 mm diameter pileus, reduced hymenium, nonamyloid basidiospores, lack of cystidia, the presence of clamps, and no incrusted pigment of the pileipellic hyphae. Phylogenetic analysis using ITS sequence data confirmed that it arised from a pathway separate from other species of Arrhenia.