Distribution: N - Ven, TAA (Hafellner 1979), Lomb, Piem (Favero-Longo & al. 2015), VA (Hafellner 1979, Piervittori & Isocrono 1999, Matteucci & al. 2015c), Lig (Brunialti & al. 1999, Ravera & al. 2022). C - Tosc, Marc (Nimis & Tretiach 1999), Laz, Sar (Monte 1993, Nöske 2000, Rizzi & al. 2011, Giordani & al. 2013, Neuwirth 2018, Brackel & Berger 2019). S - Camp, Pugl, Bas (Nimis & Tretiach 1999), Cal (Puntillo 1996, Brackel & Puntillo 2016), Si (Nimis & al. 1996b, Grillo & al. 1996, Grillo 1998, Grillo & Caniglia 2004, Brackel 2008b).
Description: Thallus squamulose to subcrustose, episubstratic, forming up to 1-2 cm wide patches, without a distinct prothallus, the squamules contiguous, 0.5-1 mm wide, usually convex, matt to shiny, epruinose, chestnut brown to rarely grey-brown, smooth. Cortex of anticlinally arranged, cellular hyphae, the terminal cells swollen, with brown caps, with a thin epinecral layer; medulla white, lacking calcium oxalate crystals, I-. Apothecia lecideine, black, 0.3-1 mm across, with an initially flat, then convex disc and a thin, finally excluded proper margin. Proper exciple narrow, poorly differentiated, aethalea-type, the outer hyphae parallel, moderately swollen and usually strongly carbonized, the inner part paler; epithecium olive-brown to almost black; hymenium colourless, 50-80 µm high, not inspersed with oil droplets, K/I+ blue; paraphyses simple to sparingly branched in upper part, 1.5-2.5 µm thick at mid-level, the apical cells 3-5 µm wide, with a brown cap; hypothecium deep reddish brown. Asci 8-spored, broadly clavate, Bacidia-type. Ascospores 1-septate, not constricted at septum, brown, oblong to ellipsoid with obtuse ends, 10-15(-17) x 5-8.5 µm, the septum narrow, not thickening during spore ontogeny, the internal walls of uniform thickness, smooth but the outer wall weakly ornamented in old spores. Pycnidia rare, urceolate to globose. Conidia bacilliform, 4-5 x 1-1.5 µm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a holarctic, subtropical to boreal-montane lichen found on steeply inclined, base-rich siliceous rocks, which starts the life-cycle on other lichens, later becoming autonomous.