Entoloma hygropileum sp. nov. (Entolomataceae, Basidiomycota) from a ‘brejo de altitude’ forest in Brazil and its Western Gondwana counterpart

A new species of Entoloma subg. Entoloma is described from a forest fragment in Northeast Brazil. The species description is based on macro and micro-anatomical characterization of the basidiomata, and molecular phylogenetic analyses of ITS and 28S LSU region of nuclear ribosomal DNA. Entoloma hygropileum sp. nov. is distinguished by the tricholomatoid to somewhat clitocyboid habit with very moist to almost slimy and glabrous brownish pileus, broadly adnate lamellae with subdecurrent tooth, proportionally short stipe, isodiametric to subisodiametric basidiospores 6.8–8.6 × 6.1–7.6 µm, absence of hymenial cystidia and a callidermic pileipellis. The most similar species is E. djaense that primarily differs in the proportionally much longer stipe and the lamellae attachment. They present a pileipellis construction unique among the genus, suggesting a Western Gondwana distribution.