Anthostomella is polyphyletic comprising several genera in Xylariaceae

Anthostomella has long been regarded as a large, but polyphyletic genus in the family Xylariaceae, but species in this group generally lack phylogenetic data. In this study, 14 anthostomella-like taxa collected from Italy, were studied using both morphology and molecular data. Single ascospore isolates were obtained and the asexual morphs of five taxa established. The phylogenetic relationships of the xylariaceous taxa were inferred using combined ITS, RPB2, beta tubulin and LSU gene regions. We introduce new sequence data for 24 with included the 14 new anthostomella-like taxa. The subfamilies Hypoxyloideae and Xylarioideae within Xylariaceae were recognized as the two major clades with high bootstrap support. Within the two clades 21 subclades were resolved and the anthostomella-like taxa clustered in five of these subclades indicating that the genus is polyphyletic. Anthostomella sensu stricto comprised A. forlicesenica, A. formosa, A. helicofissa, A. rubicola and A. obesa. The A. formosa and A. rubicola collections morphologically closely resemble the type specimens and therefore we designate reference specimens. Three new species Anthostomella helicofissa, A. forlicesenica and A. obesa are also introduced. Four distinct lineages of anthostomella-like taxa correspondent to four new genera, Anthocanalis, Brunneiperidium, Lunatiannulus and Pyriformiascoma, which are also introduced, while one clustered in Astrocystis and is introduced as a new species. Keys to the new anthostomella-like genera and species examined in this study are provided.