Marasmiellus griseobrunneus sp. nov. (Omphalotaceae) from Kerala State, India

Marasmiellus griseobrunneus sp. nov. is described from Kerala State, India, on the basis of both morphology and molecular phylogeny. This species is characterized by a grayish brown, sulcate-striate pileus with a fimbriate margin, weakly to strongly intervenose lamellae, pip-shaped to short lanceolate or lacrymoid basidiospores, versiform cheilo- and pleurocystidia, subregular hymenophoral trama, and the presence of appressed or ascending setae on the pileipellis and stipitipellis. A detailed description, comparison with both morphologically and phylogenetically related species, photographs of both the basidiocarps and the microscopic structures, and a Maximum Likelihood phylogram, based on the sequence of the Internal Transcribed Spacer region of the nuclear ribosomal DNA, depicting the placement of the new species are provided.