Distribution: N - Ven, Piem (TSB 32949). C - Abr (Nimis & Tretiach 1999, Gheza & al. 2021).
Description: Thallus crustose, endosubstratic, not apparent. Apothecia lecanorine, immersed in pits in the rock at least when young, later sometimes subsessile, 0.2-0.6 mm across, with a flat, dark brown to black, pruinose disc, and a thin, smooth, entire thalline margin. Thalline exciple corticate, the cortex usually more or less obscured by crystals which are insoluble in K, but soluble in N; epithecium blue-green, not granular, K-, N+ purple; hymenium colourless, 50-60 μm high; paraphyses slender, simple, free in K; hypothecium colourless, without granules. Asci 8-spored, clavate, very thin-walled, with a K/I+ blue, tall tholus penetrated by a faintly amyloid apical cushion, the wall K/I-, surrounded by a blue outer layer, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, 9-11 x 5.5-6.5 μm. Photobiont chlorococcoid. Spot tests: thallus (apothecial margin) K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: restricted to areas near or above treeline, this calcicolous taxon is certainly more widespread in the Alps, where it reaches the nival belt, and is also known from the central Apennines.