Remarks: Gloeosoma was defined as a taxon growing on dead branches of Nothofagaceae in Patagonia and remained monotypic over the years. A lack of information on G. vitellinum in phylogenetic studies precluded any conclusion regarding its taxonomic sta-tus. It was a matter of personal decision whether to accept the genus or consider it a synonym of Aleurodis-cus, as the microscopic features were quite typical of the latter in a broad sense.
Our study includes sequences of G. vitellinum for the first time and shows that together with G. zealandicum, G. mirabile, and Gloeosoma decor-ticans, sp. nov. (described below), they form a well- defined group of species with strong phylogenetic sup-port. This group clustered in the Stereaceae clade but was distant from A. amorphus (Pers.) J. Schröt., the type species of Aleurodiscus. The latter differs from Gloeosma morphologically by the simple-septate generative hyphae.