Pertusaria yunnana G. L. Zhou & Lu L. Zhang from south-western China is described as new to science. This corticolous species is characterized by the white pruinose disciform apothecia, asci with 8 ascospores, and the presence of atranorin in addition to fumarprotocetraric acid. Related lichen taxa are discussed and a key to 21 corticolous species of Pertusaria with disciform apothecia and 8-spored asci is also provided. atranorin, lichen, Pertusariaceae, taxonomy