Published online by Cambridge University Press: 22 August 2006
Two new Pertusaria species with brown ascospores are described from southern California and Baja California, Mexico. Pertusaria islandica sp. nov. is characterized by pertusariate to pseudolecanorate ascomata, ellipsoid ascospores, 8-spored asci, a strongly K+ violet reacting epithecium, and the presence of the 2′-O-methylperlatolic acid chemosyndrome, while P. occidentalis sp. nov. has pertusariate ascomata, globose to subglobose ascospores, 8-spored asci, and contains the arthothelin chemosyndrome. Pertusaria ochracea Kremp. is reduced to synonymy with P. melanospora Nyl.