Morphological and molecular evidence for new species and new records of Pseudosperma (Inocybaceae) in central Italy

Abstract This study presents the results of fungal surveys conducted between 2023 and 2025 to investigate the biodiversity of the genus Pseudosperma across multiple sites in central Italy. Sampling encompassed a broad range of habitats, including thermophilous woodlands on mid-hill slopes dominated by Quercus spp., riparian zones dominated by willow and poplar, and urban parks characterized by varying altitudes and vegetation types. Based on integrated morphological and molecular evidence, we describe two new species: P. polymorphocystidiatum and P. olivaceoluteum . In addition, we report four species for the first time from Italy: P. aureocitrinum , P. permelliolens , P. ushae , and P. pollucis . Phylogenetic analyses were performed using Internal Transcribed Spacer (ITS) and nuclear large subunit (nc LSU rDNA) regions of ribosomal DNA, and part of the RNA Polymerase II second largest subunit gene ( RPB2) , complemented by detailed morphological comparisons with related taxa. These findings refine the phylogeny of the Pseudosperma clade and contribute to updating the checklist of basidiomycetes in central Italy.