Distribution: N - Piem (Isocrono & al. 2003), VA (Piervittori & Isocrono 1999). C - Sar (Nöske 2000).
Description: Thallus crustose, episubstratic, rather thin, areolate, pale yellowish green, often delimited by a black prothallus. Areoles contiguous, angular, flat to rarely convex, smooth, 0.3-0.8(-1) mm wide, developing on a black hypothallus. Medulla white, I-. Apothecia lecideine, black, 0.3-0.8 mm across, at first immersed in the areoles, later adnate and apparently located between the areoles, with a flat to slightly convex disc, and a thin, soon excluded proper margin. Proper exciple dark brown; epithecium olive brown-green to dark bluish; hymenium colourless; paraphyses coherent, simple or very sparingly branched; hypothecium colourless. Asci 8-spored, clavate, Lecanora- type. Ascospores 1-celled, hyaline, ellipsoid, 11-15 x 5-7 μm. Pycnidia, black, immersed. Conidia thread-like, curved, 20-32 x c. 0.5 μm. Photobiont chlorococcoid. Spot tests: thallus K- or K+ faintly yellow, C-, KC- or KC+ yellowish, P-, UV+ pink. Chemistry: usnic acid.
Note: a species of steeply inclined to vertical surfaces of very hard siliceous rocks rich in quartz, in seepage tracks, near or above treeline.