http://www.diva-portal.org This is the published version of a paper published in Fungal diversity.

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.

Tremellomycetes are one of the most species rich group of lichen-associated basidiomycete fungi. Yet very little is known about the biology of the lichen-associated species. We present new information on the life cycle of two such species and gives new and important insights into the specificity of their symbiotic interactions with Lecanora lichens. Our study adds to the growing body of recent findings documenting the occurrence of basidiomycete yeasts in lichen thalli, and highlights that current estimates of distribution, frequency of occurrence and species specificity of lichen-associated tremellalean fungi need to be revisited.

New data on the diversity and geographical distribution of lichenicolous Tremellales and Filobasidiales in the Nordic countries is presented. One new species, Tremella rhizocarpicola, is formally described. Tremella pertusariae and T. protoparmeliae are reported as new to the Nordic countries, Syzygospora physciacearum is new to Iceland, Tremella rinodinae is new to Sweden, and T. caloplacae is new to Norway. Nine species are reported as new to a number of Swedish provinces, including Biatoropsis usnearum, Syzygospora bachmannii, S. physciacearum, Tremella caloplacae, T. cetrariicola, T. cladoniae, T. coppinsii, T. diploschistina, and T. hypogymniae.

No abstract