Phylogenetic relationships of five genera of Xylariales and Rosasphaeria gen. nov (Hypocreales)

Eight inconspicuous non-stromatic perithecial fungi immersed in plant tissue are assessed with respect to their morphology, ecology and phylogenetic position. Emphasis is laid on two genera now and then placed in the family Hyponectriaceae, Xylariales: Leiosphaerella with its type species L. praeclara occurring on Vaccinium, and Pseudomassaria with its type species P. chondrospora occurring on Tilia. In molecular phylogenetic analyses of LSU and ITS sequences, the generic types of these genera are closely related, but their familial affiliation within Xylariales remains unresolved. Pseudomassaria sepincoliformis clusters with P. chondrospora, whereas P. fallax is not congeneric with Pseudomassaria and P. lycopodina is combined in Leiosphaerella despite its apiospores. Three species thought to belong to Leiosphaerella are re-assessed: L. moravica that occurs on Rosa, is disposed in the new genus Rosasphaeria, which is close to Eucasphaeria in the Niessliaceae (Hypocreales), according to multi-gene phylogenetic analyses (ITS, LSU, rpb2 and tef1). For L. vexata the genus Pseudomassariella is revived. A Leiosphaerella-like fungus on Lycopodium is described as the new species Monographella lycopodina. In addition the phylogenetic relationships of two fungi forming superficial stromata are here clarified: Collodiscula japonica belongs to the Xylariaceae, while Melogramma campylosporum may currently be interpreted as representing a family of its own, the Melogrammataceae.