Mycena guldeniana – a new alpine species from Norway

Mycena guldeniana (section Polyadelphia) is proposed for an agaric found in alpine areas of south Norway that is here described, illustrated and compared with other species of the section. The new species grows on fallen, decaying leaves under Salix spp. or occasionally on small twigs in the same habitat and is characterized by its small size, greyish brown pileus, 4-spored basidia, smooth cheilocystidia, prominent, wide terminal cells of the pileipellis hyphae, and clamp connections. Phylogenetic analyses of nucLSU support the taxon within Mycena and genetically distinct from the morphologically similar M. terena.