Thallus: fissured to areolate, with thin to moderately thick verrucae; margins: entire, unzoned upper surface: whitish gray to yellowish gray, rugose-plicate, dull, pruinose; lacking soredia or isidia fertile verrucae: concolorous with thallus, lecanorate, numerous, c. 0.2-1.0 mm in diam. Apothecia: 1 (-4) per verruca; disc: pink, sunken, heavily whitish pruinose; epithecium: dark brown to black, K-; hypothecium yellowish asci: clavate, 170-260 x 35-78 µm, 1-spored ascospores: hyaline, fusiform to cylindrical, 130-210 x 28-64 µm; spore wall: c. 2-8 µm thick, smooth; apices: up to 30 µm thick, 1-layered Pycnidia: not seen Spot tests: K-, C+ red, KC-, P-, UV- Secondary metabolites: lecanoric acid and lichexanthone (both major) and orsellinic acid (minor). Substrate and ecology: on bark of Quercus species World distribution: cosmopolitan Sonoran distribution: coastal California and inland mountains of Mexico. The Californian material was collected at 200-400 m, while the Sinaloan specimen was collected at 2300 m altitude. Notes: Pertusaria velata is characterized by disciform ascomata with pruinose to sorediate discs, single-spored asci, and the presence of lecanoric acid and lichexanthone (the latter is lacking in some specimens).