A new cryptic species of the fungal genus Acrogenospora (Dothideomycetes, Ascomycota) from Taiwan

Acrogenospora taiwanica, found on dead terrestrial wood from Taiwan, is described as a new species based on low ITS and RPB2 identities with other species. Although the internal transcribed spacer rDNA (ITS) sequence of this species is reproducible and sufficiently comparable to that of A. thailandica, the 3’end cannot be aligned with that of other species. Since these ITS sequences indicate unresolved, atypical features, and ITS sequences are lacking for several other molecularly characterized species, the ITS sequences in Acrogenospora are shown to have limited suitability for species barcoding and phylogenetic analyses. Morphologically, the species can hardly be distinguished from A. sphaerocephala, A. terricola, and A. thailandica. Since Acrogenospora species are known to sporulate only under terrestrial conditions, their reports from submersed wood seem due to a convenient collection and incubation strategy rather than a submersed aquatic life cycle. The case of Acrogenospora indicates that“freshwater fungi”include a high proportion of terrestrial fungi, as this term is broadly applied to fungi that are able to grow on submersed substrates low in oxygen but sporulate only under terrestrial conditions.