A revision of Pertusaria species with hyaline ascospores in southwestern North America (Pertusariales, Ascomycotina)

The species belonging to Pertusaria occurring in southwestern North America are revised. 28 taxa are accepted. Descriptions of the species not treated in earlier monographs and a key to the taxa are included. The new species P, brattiae Lumbsch & Nash and P. neolecanina Lumbsch & Nash are described. P. arizonica is reduced to synonymy with P. tejocotensis, P. arsenei with P. pseudocorallina, and P. coccopoda with P. moreliensis. Pertusaria mesotr opa is a new record for North America; P. azulensis and P: mariae are repor ted from the U.S. for the first time; and P. peudocorallina, P. rubefacta, and P. texana are new to Me,rico. For some species, range extensions of the known distribution within North America are recorded.