A new species of Luteodorsum (Basidiomycota: Gomphales) from Ontario, Canada

An unrecognized mushroom resembling Gomphus was found in several localities in southern Ontario and has been identified and described through morphological and molecular phylogenetic analyses. Marker genes used include the nuclear ribosomal internal transcribed spacer region (nITS), nuclear large ribosomal subunit (nLSU), mitochondrial small ribosomal subunit (mtSSU), and mitochondrial adenosine triphosphate 6 gene (mtATP6). A multigene maximum likelihood phylogenetic tree using nLSU, mtSSU, and mtATP6 placed the novel mushroom in the previously monotypic genus Luteodorsum (Gomphales) with Luteodorsum huanglongense, from which it differs by its paler basidiomes and hymenium and narrower basidiospores. The mushroom is characterized by its velvety, creamy buff, fan-shaped or vase-like fruiting body and wrinkled hymenium. The ochraceous spores are ornamented with warts and the clamped hyphae of the basal mycelium are smooth but covered in abundant calcium oxalate crystals. These results support recognition of the Ontario collections as a new species of Luteodorsum, expanding the known geographic range of the genus and contributing to the knowledge of gomphoid diversity in North America.