Eurodistus sichuanense gen. et sp. nov., a novel lineage within Herpotrichiellaceae (Chaetothyriales)

Herpotrichiellaceae is a well-defined family within Chaetothyriales and exhibits broadly paraphyletic and polyphyletic relationships in current phylogenetic analyses. In present study, an undescribed fungus was collected from a dead branch of a terrestrial dicotyledonous plant in Sichuan Province, China, and introduced as a new genus, Eurodistus, in the Herpotrichelaceae. Phylogenetic analyses of combined internal transcribed spacer (ITS), the partial nuclear ribosomal large subunit rRNA (LSU), the nuclear ribosomal small subunit rRNA (SSU), and the partial beta-tubulin gene (tub2) sequence data positioned Eurodistus within the genus Veronaea in Herpotrichiellaceae.

Eurodistus is distinguished from other genera in Herpotrichiellaceae by its acrogenous, solitary, obclavate, elongated, and distoseptate conidia. These morphological characteristics primarily correspond to certain species in Distoseptispora, Sporidesmium, and Linkosia in Sordariomycetes, as well as Corynespora and Sporidesmiella in Dothideomycetes. However, such morphology have not been previously documented in the family Herpotrichiellaceae (Eurotiomycetes).

Our study expands the known morphological diversity within Herpotrichiellaceae and further highlights the polyphyletic nature of the family.