Description: Thallus squamulose, of loosely attached, 1-3 mm wide, 0.25-0.4 mm thick, scattered to contiguous, rounded to slightly lobate, flat squamules with deflexed to revolute margins. Upper surface pale to medium brown, matt; lower surface pale brown, attached by colourless, up to 6.5 µm thick rhizohyphae. Upper cortex 25-55 μm thick, paraplectenchymatous, with or without a thin epinecral layer; medulla white in upper part, brownish in lower part, of spherical hyphae; lower cortex not clearly delimited from the medulla. Perithecia black, subglobose, up to 0.4 mm wide, immersed in the squamules, without involucrellum. Exciple pale, darkening with age; paraphyses absent, substituted by 30-40 μm long periphyses. Asci 8-spored, clavate, the wall I-, with biseriatey arranged spores. Ascospores 1-celled, hyaline, ellipsoid, 11-15 x 5.5-8 µm. Pycnidia laminal, black, immersed; Conidia oblong-ellipsoid to subcylindrical, 3-4.5 x 1-1.8 µm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: on steeply inclined to underhanging surfaces of base-rich or calciferous rocks, sometimes on soil in rock fissures, mostly in warm-dry situations, e.g. in grasslands and garrigues; perhaps more widespread in Mediterranean Italy.