Distribution: N - TAA, Lomb, Piem (Isocrono & al. 2004), VA (Piervittori & Isocrono 1999).
Description: Thallus crustose, episubstratic, to 2 mm thick, pinkish grey, pale brown or yellowish pink, areolate-verrucose, often sorediate, usually delimited by a dark prothallus. Areoles to 1.2 mm wide, convex, sometimes bullate, rounded to angular by mutual compression (especially in the central parts of thallus), often sorediate along the margins. Medulla white, I+ blue. Cephalodia arising mainly between the areoles, pinkish or reddish brown, 0.5-1.4 mm wide, with a tuberculate surface. Apothecia rare, arising between the areoles and usually not protruding, lecideine, to 1 mm across, with a mostly flat, black, epruinose, roughened disc and a thin, brownish black, soon excluded proper margin. Proper exciple poorly developed, brown, of conglutinated, radially arranged hyphae; epithecium brownish black, covered in a granular, black latyer; hymenium colourless, to 150 μm high, I+ blue; paraphyses conglutinate, slender, branched and anastomosing, not or only slightly tickened at tips, often moniliform in upper part; hypothecium dark brown. Asci 8-spored, narrowly cylindrical-clavate, with a I+ blue tholus and an internal, darker I+ tubular structure, the external gel I+ faintly blue, Porpidia-type. Ascospores 1-celled, hyaline, ellipsoid, 22-27 x 9-15 μm, when young with a thin perispore. Pycnidia black, immersed. Conidia short-acicular, straight, 7-10 μm long. Photobiont chlorococcoid; cephalodia with Stigonema. Spot tests: cortex K-, C+ red, KC+ red, P-; medulla K-, C-, KC-, P-. Chemistry: cortex with gyrophoric acid and traces of lecanoric acid.
Note: an arctic-alpine to boreal-montane, incompletely circumpolar species of weathered, mineral-rich siliceous rocks close to the ground, in areas with late snow-lie.
Growth form: Crustose
Photobiont: green algae other than Trentepohlia (primary); cyanobacteria, filamentous (e.g. Nostoc, Scytonema) (secundary, e.g. in cephalodia)