Examination of the generic concept and species boundaries of the genus Erioscyphella (Lachnaceae, Helotiales, Ascomycota) with the proposal of new species and new combinations based on the Japanese materials

The genus Erioscyphella Kirschst., which was morphologically confused with Lachnum, was herein examined. Based on molecular phylogenetic analyses using a combined dataset of ITS, LSU, mtSSU, and RPB2 and morphological examinations, Erioscyphella was distinguished from Lachnum and redefined by longer ascospores and the presence of apical amorphous materials and/or resinous materials equipped on hairs. Species boundaries recognized by morphology/ecology and phylogenetic analyses were cross-checked using species delimitation analyses based on DNA barcode sequences downloaded from UNITE, resulting in that species’ taxonomic problems being uncovered. Six new species (E.boninensis, E.insulae, E.otanii, E.papillaris, E.paralushanensis, and E.sasibrevispora) and two new combinations (E.hainanensis and E.sinensis) were proposed.