Description: Thallus crustose, thinly episubstratic, 0.2-0.4 mm thick, of 0.3-0.6 mm wide, more or less flattened, pale ochraceous areoles with a whitish margin, scattered in depressions of the rock, most often poorly evident, without a distinct prothallus. Medulla I-. Apothecia lecideine, black, with a smooth disc and a raised proper margin. Epithecium green to blue-green, 13-17 µm high; hymenium colourless, 50-60 µm high; paraphyses coherent; hypothecium colourless to pale green. Asci 8-spored, narrowly clavate, thick-walled, with a K/I+ pale blue tholus and a strongly amyloid, thin apical cushion, surrounded by a I+ blue outer layer, Lecidea-type. Ascospores 1-celled, hyaline, ellipsoid, 9-12 x 5-6 µm. Photobiont chlorococcoid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: unknown, but probably thallus without lichen substances.
Note: known only from the type collection and from a single record from Austria, this silicicolous species found above treeline is related to L. atrobrunnea. Indicator values are tentative.