Xenosporidesmium L. L. Liu & Z. Y. Liu 2025, gen. nov.

Xenosporidesmium L. L. Liu & Z. Y. Liu gen. nov. Etymology. “Xeno-” means different, “ Xenosporidesmium ” reflects that, although this fungus resembles Sporidesmium in morphology, it is genetically distinct and phylogenetically separate. Type species. Xenosporidesmium aquaticivaginatum (Jiang Yang & K. D. Hyde) L. L. Liu & Z. Y. Liu, comb. nov. Description. Saprobic on dead wood. Sexual morph: Undetermined. Asexual morph: Colonies on nature substrate effuse, hairy, scattered or in small groups. Conidiophores macronematous, mononematous, solitary, cylindrical, straight or slightly flexuous, dark brown, septate. Conidiogenous cells holoblastic, monoblastic, integrated, terminal, determinate or with one percurrent proliferation, cylindrical, smooth, pale to dark brown. Conidia acrogenous, solitary, obclavate, pale brown to olivaceous, paler at the apex, tapering gradually towards the apex, smooth, straight or curved, distoseptate, with a mucilaginous sheath or apical appendage. Notes. The new genus Xenosporidesmium is established to accommodate seven species, including one newly discovered taxon and six species previously classified in Sporidesmium. Xenosporidesmium aquaticivaginatum (= Sporidesmium aquaticivaginatum) is designated as the type species because its epithet reflects the aquatic habitat preference characteristic of this genus, although it was published concurrently with X. olivaceoconidium in the same work (Hyde et al. 2016). In this study, we introduce one new Xenosporidesmium species and transfer Sporidesmium aquaticivaginatum, S. filiforme, S. guizhouense, S. guttulatum, S. nujiangens, and S. olivaceoconidium to Xenosporidesmium based on phylogenetic analyses.