Thallus: fissured to fissured-areolate, with thin to moderately thick verrucae; margins: entire, unzoned upper surface: gray to dark gray, smooth, dull or shiny, epruinose to gray-white pruinose; lacking soredia or isidia fertile verrucae: concolorous with thallus, lecanorate, numerous, c. 0.5-1.5 mm in diam. Apothecia: 1-3 per verruca; discs: black, sunken, grayish pruinose; epithecium: dark brown to blackish brown; hypothecium: yellowish to hyaline asci: cylindrical, 120-250 x 20-45 µm, 8-spored ascospores: hyaline, ellipsoid to fusiform, 25-50 x 14-24 µm; spore wall: c. 2-5 µm thick, smooth, 1-layered Pycnidia: immersed conidia: bacilliform, 7-10 x 0.5-1.0 µm Spot tests: K- or + pale yellow, C-, KC-, P- or + yellow to orange, UV- Secondary metabolites: stictic acid (major), constictic and norstictic acids (both minor). Substrate and ecology: on siliceous rocks in coastal mountains World distribution: western North American and disjunct in the Mediterranean region Sonoran distribution: restricted to coastal California. Notes: Pertusaria chiodectonoides is characterized by a generally dark gray thallus with lecanorate verrucae with pruinose, blackish discs, a K+ violet epithecium, 8-spored asci, and the presence of stictic acid. It may be confused with P. brattiae which contains norstictic acid and has 2-4-spored asci. No recent collections of P. chiodectonoides from North America are known.