A new Biatoridium from eastern North America, with comments on the disposition of species of Biatorella sensu Magnusson

Biatoridium lasiothecium is described as new to science from southeastern North America. The species differs from B. delitescens and B. monasteriense in the shaggy appearance of the ascomata, due to the elongation of individual paraphyses. A taxonomic key to morphologically similar, polysporous species, as well as other North American lichenized and non- lichenized fungi traditionally included in Biatorella, is provided. A new combination is made for Strangospora cyphalea ( B. cyphalea).