Morphological and phylogenetic analyses reveal Xenosporidesmiaceae fam. nov, with seven Xenosporidesmium species

This study introduces a new family, Xenosporidesmiaceae, and describes a novel genus, Xenosporidesmium, along with a new species, Xenosporidesmium caohaiense, based on morphological and phylogenetic analyses. Multi-locus phylogenetic reconstruction (LSU, SSU, ITS, and rpb 2) revealed that the new family forms a distinct clade, diverging from Sporidesmiales and Distoseptisporales in Sordariomycetes, and supporting its taxonomic independence.

The new species, X. caohaiense, is characterized by dark brown conidiophores and pale brown, distoseptate conidia with mucilaginous sheaths. Additionally, six previously described Sporidesmium species are reclassified into Xenosporidesmium. This study emphasizes the significance of molecular data in resolving taxonomic ambiguities among morphologically similar but phylogenetically divergent fungi, thereby contributing to the understanding of freshwater fungal diversity.