An integrative taxonomic study on Parasola (Psathyrellaceae, Fungi) reveals a new saprotrophic species from European temperate deciduous forests

Seventeen collections of the genus <em>Parasola</em> from Croatia were studied by integrative taxonomic methods. <em>Parasola papillatospora</em> is described as a new species, based on morphology and multigene phylogenetic analyses. Its basidiomata were growing on soil in temperate deciduous forests (<em>Quercus petraea</em>, <em>Fagus sylvatica</em>, and <em>Carpinus betulus</em>) on two different localities in NW Croatia<em>.</em> Based on publicly available molecular data, the species is recorded also in Hungary. The most distinctive morphological features of the new species are the characteristics of its basidiospores, (1) papillate apex and (2) central germ pore (both present in most spores), as well as (3) highly variable shape. In this study, a total of 64 DNA sequences from 17 specimens belonging to 10 <em>Parasola</em> species were newly generated. As a result of Bayesian Inference and Maximum Likelihood phylogenetic analyses of the concatenated ITS, LSU, <em>tef-1α</em>, and <em>β-tub</em> gene alignment of <em>Parasola </em>species, <em>P. papillatospora </em>was resolved as an independent clade, sister to the clade comprising<em> P. plicatilis</em> species complex. Eight <em>Parasola</em> species (<em>P. auricoma</em>,<em> P. crataegi, P. cuniculorum, P. kuehneri, P. malakandensis, P. megasperma</em>, <em>P. nudiceps, P. plicatilis-similis</em>) are reported for the first time for Croatia and <em>P. malakandensis</em> also for Europe. A morphological description of <em>P. papillatospora</em> is accompanied by colour photographs of basidiomata, basidiospores, and cystidia. For <em>Parasola</em> species new to Croatia (all except <em>P. kuehneri</em>), colour photographs of basidiomata are provided.