Thallus: crustose, areolate, up to 30 mm in diam., 0.15-0.35 mm thick; prothallus: black, visible along thallus margin and between areoles areoles: plane to +convex or bullate, angular, 0.2-0.8 mm in diam. upper surface: gray to red-brown to dark brown in exposed situations, rough to rarely smooth, rarely sorediate soredia: black cortex: green-gray to brown-green, 10-20 µm thick; medulla: white; algal layer 70-100 µm thick Apothecia: black, immersed initially, becoming sessile, 3-4 mm in diam. (often smaller) disc: black, flat, finally convex, dull, epruinose; margin: black, distinct and persistent, dull true exciple: distinct (sometimes becoming excluded), with a 10-25 µm thick greenish gray or greenish black to black cortex and an unpigmented, opaque medullary part (rarely dark brown), 35-75 µm thick, composed of hyphae 3.5-4.5 µm in diam. epihymenium: green, occasionally incrusted with pale blue to violet granules, sometimes totally violet (responsible for the epithets "epiiodiza" and "endocyanea") hymenium: hyaline, 60-90(-110) µm tall, I+ blue; paraphyes: branched apically, not anastomosing, 1.5-2 µm wide below, 2.5-3(-4) µm wide apically; subhymenium: hyaline, 30-55 µm thick; hypothecium: hyaline to light brown or dark brown, 60-180 µm thick asci: +cylindrical, 55-75 x 10-12 µm, 8-spored ascospores: elongate ellipsoid to broadly obpyriform, (9-)11-14(-17) x (4-)5-7(-9)µm Pycnidia: immersed conidia: cylindrical, 4-7 x 0.9-1 µm Spot tests: cortex, medulla and exciple K-, C+ pink, KC+ pink, P- Secondary metabolites: cortex and medulla with gyrophoric acid (major) and lecanoric acid (minor). Substrate and ecology: in open habitats on granites, schists and other acidic rocks World distribution: North America, Europe, Asia, Australasia, and the subantarctic islands Sonoran distribution: montane in central and SE Arizona.