Distribution: N - TAA, Lomb, VA (Piervittori & Isocrono 1999), Lig (Giordani & al. 2016).
Description: Thallus crustose, sometimes indistinct, usually thinly episubstratic, granulose or rimose- areolate 0.1-1 mm thick, often delimited by a dark prothallus. Areoles 0.2-0.6(-2.4) mm wide, white, rough. Medulla I-. Apothecia lecideine, glossy black, sessile, 0.5-0.7(-1) mm across, with a flat to convex, epruinose disc, and a prominent, usually persistent, strongly flexuose proper margin. Proper exciple blue-green in outer part, dark brown within; epithecium bright green to blue-black, N+ purple; hymenium colourless or rarely greenish in upper part, 45-70 µm high, inspersed with oil droplets; paraphyses rather loose, distinctly thickened at apex; hypothecium orange-brown or yellowish brown, rarely colourless. Asci (4-)8-spored, clavate, very thin-walled, with a tall apical dome, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, 8-15 x 4-8 µm. Pycnidia globose, immersed. Conidia thread-like, 10-20 µm long. Photobiont chlorococcoid. Spot tests: thallus K- or K+ faintly yellow, C-, KC-, P-. Chemistry: atranorin and 2'-O-methylperlatolic acid.
Note: an early coloniser of small pebbles in dusty situations, especially near the ground, with a wide altitudinal range.