Physconia labrata, a new species from western North America and Asia

A new species belonging to the lichen genus Physconia is described from Alaska and the Canadian and American Rocky Mountains and adjacent forested regions. It is also reported from China, Nepal, India and Siberia. The new species, Physconia labrata, is superficially similar to P. perisidiosa, but can be distinguished by having a blackened, corticate lower surface and a paraplectenchymatous upper cortex.