Multi-locus phylogeny supports the placement of Endocarpon pulvinatum within Staurothele s.str. (lichenised ascomycetes, Eurotiomycetes, Verrucariaceae)

Within the lichen family Verrucariaceae, the genera Endocarpon, Willeya and Staurothele are characterised by muriform ascospores and the presence of algal cells in the hymenium. Endocarpon thalli are squamulose to subfruticose, whereas Willeya and Staurothele include only crustose species. Endocarpon pulvinatum, an arctic-alpine species newly reported for Iceland, is one of the few Endocarpon with a subfruticose thallus formed by long and narrow erected squamules. Molecular phylogenetic analyses of four loci (ITS, nrLSU, mtSSU, and mcm7) newly obtained from E. pulvinatum specimens from Iceland, Finland and North America does not confirm its current classification within the mostly squamulose genus Endocarpon, but instead supports its placement within the crustose genus Staurothele. The new combination Staurothele pulvinata is therefore proposed here. It includes also E. tortuosum, which was confirmed as a synonym of E. pulvinatum based on a single sequence.