Three new species in the Biatoropsis usnearum complex

Three new species of Biatoropsis are formally described based on our previous molecular studies, and on additional molecular, morphological, and ecological data. Biatoropsis protousneae sp. nov. is confined to Protousnea dusenii. Biatoropsis minuta sp. nov. is characterized by the small and brown to black basidiomatal galls, and by growing on Usnea barbata and U. lapponica. Biatoropsis hafellneri sp. nov. is distinguished by 2-celled basidia with cells that elongate laterally at maturity, and by growing on species of the Usnea fragilescens aggregate. A fourth Biatoropsis species is left unnamed, and two other lineages are not described, all waiting for the study of additional material.