Additions to the genus <I>Rhytidhysteron</I> in Hysteriaceae

Rhytidhysteron (Hysteriaceae) species are widely distributed as saprobes or weak pathogens on a wide range of woody plants. In this study, several Rhytidhysteron collections were made in northern Thailand and multi-gene phylogenetic analyses were used to resolve the phylogenetic boundaries of species. Two novel species, R. thailandicum and R. neorufulum are introduced, based on morphological traits and multi-gene phylogeny. The genus is revised with a key to species.