Thallus: crustose, areolate, granulose to wavy verrucose, 0.1-0.3 mm thick; prothallus: rarely present, black to gray surface: yellowish white to creamy light gray, dull, without soredia or isidia Apothecia: sessile, slightly to strongly constricted at base, 0.2-0.8 mm in diam. disc: black to brown (if damaged ?), plane to convex, epruinose to scarcely pale grayish pruinose (if damaged ?) margin: indistinct, very thin, becoming excluded exciple: brown to grayish green, without algal cells parathecium: hyaline to sometimes pale brown, without crystals epihymenium: brown, grayish green to olive hymenium: hyaline, 55-65 µm tall, not inspersed; paraphyses: simple, rarely anastomosing or branched, slightly thickened apically hypothecium: hyaline to rarely pale brown asci: clavate, lecanoral, 8-spored ascospores: hyaline, simple, ellipsoid, 9-13 x 5-6.5 µm; wall: thick and smooth, not halonate Pycnidia: not seen Spot tests: thallus surface K-, C+ yellowish red, KC+ yellowish red, P- Secondary metabolites: 4,5-dichloronorlichexanthone, arthothelin (2,4,5-trichloronorlichexanthone), isoarthothelin (= 2,5,7trichloronorlichexanthone), and thiophanic acid (= 2,4,5,7tetrachloronorlichexanthone), in traces thuringione (= 2,4,5-trichloro-3-O-methylnorlichexanthone). Substrate and ecology: on non-calciferous rock World distribution: Europe, North and South America Sonoran distribution: relatively common at intermediate elevations of Arizona, Baja California, Baja California Sur, Sonora, and Chihuahua.