Pulverulina, a New Genus of Agaricales for Clitocybe ulmicola

A new genus, Pulverulina, is described to accommodate the monotypic lineage Clitocybe ulmicola in the Porotheleaceae. Pulverulina ulmicola is characterized by small, clitocyboid, pileate-stipitate basidiomata with a tough, pruinose stipe; distant decurrent lamellae; smooth inamyloid basidiospores; long, abundant caulocystidia; interwoven lamellar trama, and lignicolous habit on bark of living trees. A taxonomic description and illustrations are provided together with molecular phylogenetic analysis of 14 genera of Porotheleaceae. One new taxon and 3 new combinations are proposed: Pulverulina gen. nov. and Pulverulina ulmicola comb. nov., Hydropus rugosodiscus comb. nov., and Leucoinocybe auricoma comb. nov.