Atrostelia—a new genus in Megasporaceae (Pertusariales, lichenized Ascomycota)

Phylogenetic analysis based on nu ITS, nu LSU, and mt SSU ribosomal DNA fragments revealed a new genus in Megasporaceae described here as Atrostelia Paukov, Davydov & Yakovchenko. Phylogenetically, it is close to Aspiciliella but differs in radiate-placodioid thalli, large, 23–36 μm spores, and substictic acid as a secondary metabolite. The genus is represented by a single species, Atrostelia magnifica Paukov, Davydov & Yakovchenko, which is endemic to the Mongun Taiga massif, Republic of Tyva, Russia. The phylogenetic reconstruction supported 9 genera in Megasporaceae: Aspicilia, Aspiciliella, Atrostelia, Circinaria, Lobothallia, Megaspora, Oxneriaria, Sagedia, and Teuvoa, while Agrestia, Chlorangium, and Sphaerothallia were synonymous with Circinaria.