Taxonomy and phylogeny of Paramarasmius gen. nov. and Paramarasmius mesosporus, a worldwide distributed fungus with a strict ecological niche

Specimens of Marasmiellus mesosporus from various parts of the world were morphologically and phylogenetically studied. The results confirmed its identity with M. dunensis, described from southern Europe, and M. arenaceus, described from Japan. Marasmiellus mesosporus is a fungus connected with coastal sandy dunes having a wide distribution being collected in southeastern North America, Lesser and Greater Antilles, Pacific Islands, southern Europe and South and East Asia. Its comparison with phylogenetically and morphologically related species is provided. A new genus Paramarasmius containing P. palmivorus, as the type species, and P. mesosporus is described on the base of phylogenetic analyses of ITS and LSU rDNA sequences. A new combination Collybiopsis carneopallida is also proposed.