Description: Thallus squamulose to subfruticose, consisting of imbricate or dispersed squamules-branches interconnected by abundant rhizomorphs, forming large patches. Squamules-branches up to 5 mm wide, the mature ones irregularly imbricate to contiguous, frequently fused with each other laterally, generally ascending, mainly at the tips, flat to concave or strongly convex, the margins sinuate or with verrucose to subcylindrical lobules. Upper surface matt, grey or partly olivaceous to brown, frequently with white maculae consisting of accumulations of dead cortical cells, without real pseudocyphellae. Cortex 18-75(-90) µm thick, paraplectenchymatous, brown-green pigmented iin upper part, covered with an epinecral layer, without crystals; medulla white, highly variable in thickness; rhizomorphs delicate, lacking algae, whitish or yellowish to pink, later dark, up to several cm long, 1-5 mm thick, branched, with a central cord of densely packed hyphae. Apothecia lecanorine-aspicilioid, up to 3-5 mm wide, orbicular to deformed, immersed to sessile, one to several per squamule, with an initially almost urceolate, then concve to flat, black disc, and a rather thin thalline margin. Proper exciple paraplectenchymatous in outer part, brown-green to black at the surface; epithecium olivaceous to greenish, N+ green; hymenium colourless, 105-160(-175) µm high, without oil droplets; paraphyses branched and anastomosing, moniliform to submoniliform, the apical cells up to 7 µm wide; hypothecium colourless, with or without an algal layer underneath. Asci (2-)4(-6)-spored, clavate, the thin outer coat K/I+ blue, the wall and apical dome K/I-. Ascospores1-celled. hyaline, broadly ellipsoid, (1-)15-32(-45) x (8-)11-20(-31) µm, thin-walled. Pycnidia most frequent at tips of squamules, immersed, the ostiole greenish-brown to black, the wall hyaline. Conidia bacilliform, straight, 7-12 x c. 1 µm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: this characteristic subfruticulose species growing amongst mosses on siliceous substrata is hitherto known only from central Spain and Sardegna. It occurs on mosses and on exposed, more or less horizontal surfaces of granitic rocks at low elevations.