RESUMEN
Background: Mycena (Pers.) Roussel (1806) is a large genus of Mycenaceae known for having small to medium-sized basidiomata. It is typified by the species Mycenagalericulata (Scop.) Gray. For years, many mycologists have made important contributions to understanding Mycena and several monographs have been published. Three specimens were collected from China that belonged to the genus Mycena. On the basis of morphological analysis and phylogenetic analyses employing DNA sequences, a new species is described. New information: Mycenabrunnescens sp. nov. is described as a new species from subtropical areas of China. It is characterised by its brown pileus, whitish lamellae that turns brown when bruised, orange to brown lamellae edges, the absence of pleurocystidia and cheilocystidia with simple or branched excrescences at the apex containing yellowish-brown contents. We performed phylogenetic analyses on a concatenated dataset comprising the internal transcribed spacer and large subunit regions of nuclear ribosomal RNA using Bayesian Inference and Maximum Likelihood methods. The result showed that the new taxon clustered in an independent group and is closely related to M.albiceps and M.flosoides.