Taxonomia de Mycena (Agaricales) em áreas da Amazônia brasileira

The Amazon Forest harbors an enormous biodiversity including fungi which contribute to the maintenance of this biome. Mycena (Pers.) Roussel is a genus of mostly saprophytic macrofungi that significantly contribute to nutrient cycling in the forest soil. It is the most diverse genus of the family Mycenaceae, with about 600 described species, out of which 160 are recorded in Brazil. Considering the high potential for species richness in the Amazon, the scarcity of specialists and of recent taxonomic studies including the genus, the richness of these fungi in the biome is underestimated with many new species to be described. Mycena is polyphyletic in Agaricales, with most species branching in Mycenaceae and few other in the “Hydropoid” clade or Porotheleaceae. The distinction between Mycena and related genera is still unclear, as representatives of some genera branch nested within the large Mycena group including the type species. The aim of this study was to investigate Mycena species in areas of Central Amazon through taxonomy. Specimens from new collections, and recent other collections from other INPA projects were analyzed. The new sampling was carried out by simple search on trails, in the “Reserva Florestal Adolpho Ducke”, in the “Instituto Nacional de Pesquisas da Amazônia (INPA) – Campus I”, both in the municipality of Manaus, in the “Parque Nacional do Jaú” in in the municipality of Novo Airão, and in the “Reserva Terra-Floresta” located in the municipality of Presidente Figueiredo, all in the state of Amazonas, Brazil. The macro- (with photographs) and micromorphological (optical microscopy) analyzes followed the methods adopted for agaricoid fungi in the elaboration of the descriptions and illustrations. The identification of representative collections was based on the morphological analysis, comparison with previously identified specimens, and comparison with the specialized literature. The new collections were deposited in the INPA Herbarium. As a result of this study, 19 species of Mycena were identified among them M. amazonica, M. chloroxantha, M. spinosissima, M. kermesina, M. longicrinita and M. trichocephala previously reported in the Amazon; M. holoporphyra representing the first record in the Amazonas and Pará states, Brazil; M. roseotincta is firstly record in the Amazon and secondly record worldwide, and 11 are new species. The continuity of this taxonomic study will quite possibly reveal more species not still recorded in the Amazon along with more taxonomic novelties. New studies integrating molecular data are needed to clarify the phylogenetic relationship of these species and others, the infrageneric classification and the natural circumscription of the genus.