Distribution: C - Marc. S - Camp (Aprile & al. 2003b), Pugl (Nimis & Tretiach 1999), Si (Nimis & al. 1994).
Description: Thallus crustose, endosubstratic or very thinly episubstratic, when visible forming small, inconspicuous, ochraceous flecks around the apothecia. Apothecia biatorine, sessile and constricted at base, 0,15-0.3 mm across, brown to black when dry, brown with a black margin when wet, somehow glossy, with a moderately to strongly convex, epruinose disc, and a very thin, soon excluded proper margin. Proper exciple thin, of strongly branched and anastomosing hyphae, dark red-brown in outer part, somewhat paler within, K+ faintly reddish, N+ purple-red; epithecium pale yellowish brown to violet-brown, 8-11 µm high, the pigment diffuse in the gel, N+ purple-red; hymenium colourless, 50-75 µm high, I+ blue; paraphyses strongly coherent, simple or sparingly branched and anastomosing, 1.5-2.5(-3) µm thick, the apical cells up to 5 µm wide, surrounded by a pigmented gel; hypothecium colourless to pale brown in older apothecia, 75-110 µm high, I+ blue. Asci 8-spored, subcylindrical, with a K/I+ blue outer coat and a K/I+ uniformly blue apical dome. Ascopores, 1-septate, hyaline, ellipsoid, 9.5-13.5 x 4-5.5 µm. Photobiont chlorococcoid, the cells 9-15(-20) µm wide. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a temperate species growing on calcareous rocks in open situations at relatively low elevations. Ecology and distribution need further study, and the indicator values are tentative.