Two new species, Hypogymnia tuckerae and H. discopruina (Parmeliaceae), from North America and China

Abstract. Hypogymnia tuckerae is a newly described sorediate lichenized fungus currently known from three sites in the Cascade Range in Oregon, three sites in northern California, and one site in the Blue Mountains of northeastern Oregon. Although we have known a few of these anomalous sorediate specimens for many years, taxonomic action was stymied by possibilities that they were rare sorediate morphs of a normally fertile species, H. wilfiana, or a rare chemotype of a normally sorediate lichen, H. oceanica. ITS and GPD1 sequences demonstrated that neither is the case; instead, H. tuckerae occupies an isolated position in phylogenetic reconstructions. With ITS alone, however, H. tuckerae is sister to the largest clade of Hypogymnia species from the southern hemisphere. Esorediate individuals of H. tuckerae are very similar to H. antarctica (South America), H. metaphysodes (Japan), and H. wilfiana (North America). We have not yet found a reliable chemical or morphological character to separate esorediate H. tuckerae from H. wilfiana. Hypogymnia discopruina is described as a new species from southwestern China. The species is unusual for the genus in having pruinose apothecia and a POL+ epithecium. The only other Hypogymnia known to have a POL+ epithecium is H. crystallina from the Himalaya Range in India. So far H. discopruina is known from only two locations in Sichuan and Yunnan Provinces at 3000 m and 3600 m and appears to be rare. Adjustments to the keys to Hypogymnia in the Pacific Northwest of North America and for southwest China are given for these two new species and the recently described Asian sorediate species, H. caperatica.