Taxonomy of Buellia epigaea-group (Caliciales, Caliciaceae), revealing a new species and two new records from China

During the Second Tibetan Plateau Scientific Expedition and Research Program, we discovered that white terricolous lichenized fungal species of Buellia De Not. were widely distributed across the Tibetan Plateau. After examining their morphology, chemistry and phylogeny, we describe Buellia alpina Xin Y. Wang & Li S. Wang, sp. nov. as new to science. It is present in alpine meadows, and is characterized by its effigurate thallus, distinct linear marginal lobes, cover of thick white pruina and four-spored asci. This is also the first report of Buellia elegans Poelt and Buellia epigaea (Pers.) Tuck from China. The Buellia epigaea-group has previously been characterized by white and often effigurate thalli that occur mainly on soil. However, our results show that species in this group actually belong to two distinct clades. This conclusion is based on analyses of the nuITS region and the combined regions dataset (nuITS-nuLSU-mtSSU-beta-tubulin). We discuss differences in morphology, anatomy, chemistry and ecology among the putative Buellia epigaeagroup. Detailed descriptions and figures for the three species from China and a key for species of Buellia epigaea-group are provided.

Automated summary

During the scientific expedition in the Tibetan Plateau, a new species of white terricolous lichenized fungal species of Buellia De Not. was discovered. Through examinations of morphology, chemistry, and phylogeny, this new species, Buellia alpina, was described. Additionally, two other species, Buellia elegans and Buellia epigaea, were reported in China for the first time. It was found that species in the Buellia epigaea-group actually belong to two distinct clades. This research provides detailed descriptions and a key for species identification.