Description: Thallus crustose, thinly episubstratic, greenish white to yellowish white, of 0.3-1 mm wide, smooth, flattened, contiguous areoles developing on a black hypothallus, griowing on the thalli of Orphniospora mosigii. Medulla white, I-. Apothecia lecideine to biatorine, black, 0.3-0.8 mm across, semi-immersed to adnate, apparently arising between the areoles, with a flat to slightly convex, epruinose disc, and a very thin, soon excluded proper margin. Proper exciple thin, greenish black in outer part, paler within; epithecium blue-green, N+ purple-red; hymenium colourless or greenish in upper part, 50-70 µm high; paraphyses conglutinated, simple, 1.5-2 µm thick at mid-level, the apical cell to c. 2 µm wide; hypothecium colourless to pale brown. 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, 8-15 x 3-6.5 µm. Conidia thread-like, 15-30 µm long. Photobiont chlorococcoid. Spot tests: all negative or thallus K+ and KC+ faintly yellowish. Chemistry: thallus with variable amounts of usnic acid.
Note: an arctic-alpine obligate parasite on the thalli of Orphniospora mosigii, found on steeply inclined, exposed faces of hard siliceous rocks near or above treeline; the species is certainly more widespread in the Alps.