Taxonomic reassessment of two taxa of helotialean fungi

Abstract

Species of the genera Calycina, Hymenoscyphus, Dicephalospora, Lambertella, Lanzia, Rutstroemia, Ciboria, Dumontinia, Monilinia, and Rhizoscyphus often share a similar ectal excipular structure but differ in many other aspects when morphological features are concerned. A neighbor-joining tree containing the above mentioned genera based on sequence analysis of the ITS regions was established with Lachnum spartinae and L. cf. pygmaeum as outgroup. Three major clades were recognized. One clade contains most species of Hymenoscyphus (except for Hymenoscyphus rhodoleucus) as well as Lanzia microserotina; the second consists of only the Ericaceae-associated genus Rhizoscyphus; and the third includes the genera currently treated in the Sclerotiniaceae and Rutstroemiaceae, as well as two species, Hymenoscyphus rhodoleucus and Calycina herbarum. Lanzia microserotina is not closely related to Lanzia spp. but to Hymenoscyphus serotinus. Lanzia huangshanica f. aurantiaca is recognized at species level. New combinations in Hymenoscyphus and Lanzia are proposed based on the morphological and molecular data. Placement of Calycina herbarum and of Hymenoscyphus rhodoleucus are noted.