Description: Thallus crustose, episubstratic, minutely areolate, without a distinct prothallus, forming patches of 1 cm or less. Areoles 0.2-0.9(-1.5) mm wide, 0,2.0,4 mm thick, contiguous, rounded to irregular, flat to usually slighty convex, deep brown to pale reddish brown, pale and ecorticate in lower part, epruinose. Epicortex lacking or <10 μm thick. Cortex (10-)40-60 μm thick, the brown upper layer c. 10 μm thick, the lowe layer colourless; algal layer 50-100 μm thick, even, continuous or rarely interrupted by <10 μm wide hyphal bundles, continuous beneath apothecia; medulla 100-250 μm thick, mixed with substrate particles. Apothecia lecanorine, 0.1-0.25(-0.6) mm across, rounded, 1-3(-4) per areole, immersed, with a reddish brown to dark brown, epruinose, usually flat, smooth or rough disc, and a usually paler brown, raised, smooth margin, the disc tending to become pseudogyrose when old. Proper exciple indistinct or expanding up to 60 μm around the disc, often forming an elevated margin concolorous with thallus; epithecium yellowish brown, c. 10 µm high; hymenium colourless, (85-)100-140(-160) µm high, hemiamyloid; paraphyses 1-1.7 µm thick at mid-level, the apical cells cylindrical to clavate and up to 2.5 μm wide; hypothecium colourless, (20-)40-55 µm high, K/I+ blue. Asci 100-200-spored, clavate, the apical dome K/I-. Ascospores 1-celled, hyaline, narrowly ellipsoid to bacilliform, 3-5(-6) x (1-)1.5-1.7(-2) µm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a poorly known species of eutrophicated, dry and hard lignum, hitherto reported from Northern Europe and the Alps. For further details see Knudsen & al. (2021, 2021b). A dubious record from Campania by Garofalo & al. (1999) is not accepted here.