Cystoagaricus squarrosus (Psathyrellaceae, Agaricales), a new species from temperate forests of Turkey and Spain

A new lignicolous agaric, Cystoagaricus squarrosus, is described and illustrated based on collections gathered in Burdur province (Turkey) and Girona Pyrenees (Spain). This new species was found in southwestern Turkey associated with the wood of a tertiary relict endemic Liquidambar orientalis , and in eastern Spain on wood of Fraxinus excelsior . Cystoagaricus squarrosus is morphologically close to C. hirtosquamulosus and some other species of the genus, but it differs from them by its small basidioma size, the squarrose pileus, the short frustoconical basidiospores, the clavate cheilocystidia with long pedicels, the light lilac-grey pleurocystidia and the smooth parietal pigment of the veil hyphae. In addition to that species, C. lepidotoides is recorded for the first time for Turkey. Phylogenetic analysis based on molecular sequence data of nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) and partial 28S nuc rDNA sequences supports the delimitation of this new taxon as a distinct lineage within Cystoagaricus .