The new genus Pulvinora (Lecanoraceae) for species of the 'Lecanora pringlei' group, including the new species Pulvinora stereothallina

摘要

Phylogenetic reconstructions based on ITS/5.8S, mtSSU and nuLSU DNA sequence data suggest that Lecanora pringlei from North America and a closely related new species from the Altai Mountains, Russia, should be transferred to a new genus Pulvinora, phylogenetically related to Frutidella. It is distinguished by Lecanora-type asci, mycolecanorine apothecia soon becoming convex with an algal layer pushed below the hypothecium, and a pulvinate thallus with squamules at the tip of pseudopodetia-like, branched, pale brownish structures. Lecanora subcavicola and L. pringlei subsp. brandegeei do not belong to this new genus Pulvinora; consequently, we propose the new combination L. brandegeei to accommodate the latter taxon. Pulvinora stereothallina is distinguished from P. pringlei in the shape and size of its squamules (plane to concave, up to 3.0 mm long vs. remaining convex, up to 1.5 mm long), by the lack of maculae, the presence of a whitish pruina on the margins and elevated parts of its squamules, by apothecia coalescing into clusters (vs. single), an ochre-yellow to brownish (vs. colorless) proper exciple, larger ascospores, and different secondary metabolites. Lectotypes of Lecidea pringlei Tuck. and L. brandegeei Tuck. are designated here from the collections deposited in FH.