Thallus: continuous to fissured or fissured-areolate, with very thin or thin to moderately thick verrucae; margins: entire, often zoned upper surface: ash gray to dark gray, smooth to tuberculate, shiny, epruinose soredia: restricted to verrucae fertile verrucae: sorediate, concolorous with thallus, lecanorate, numerous, sometimes fusing, c. 0.4-1.2 mm in diam. Apothecia: 1 (-4) per verruca; disc: blackish brown, level to sunken, whitish pruinose, later totally sorediate; epithecium: dark brown to black, K-; hypothecium: yellowish asci: clavate to cylindrical, 110-240 x 40-80 µm, 1-spored ascospores: hyaline, ellipsoid to cylindrical, 85-190 x 25-65 µm; spore wall: c. 2-12 µm thick, 1-layered Pycnidia: immersed conidia: bacilliform, 4-7 x 0.5-1.0 µm Spot tests: K-, C-, KC-, P-, UV- Secondary metabolites: no phenolic substances detectable. Substrate and ecology: on bark of numerous phorophytes, including Abies, Alnus, Juniperus, Pinus, Pseudotsuga, and Quercus, but also occurs on dead wood World distribution: circumboreal Sonoran distribution: coastal California and mountainous areas of Arizona, Chihuahua and Sinaloa at 2000 to 3000 m. Notes: Pertusaria ophthalmiza is characterized by a gray thallus with lecanorate verrucae with a crenulate margin, a white pruinose disc which soon becomes sorediate, single-spored asci and the absence of phenolic compounds. It is hardly confused with any other Pertusaria species in southwestern North America.