Description: Thallus crustose, episubstratic, of scattered to confluent, whitish to ash-grey, usually convex or subglobose areoles. Apothecia micareoid, black or blue-black, sessile to substipitate, often tuberculate, 0.15-1 mm across, with a convex to almost globose disc, usually without a proper margin, but sometimes thinly marginate when young. Proper exciple poorly developed but evident in young apothecia, colourless or aeruginose green to olive-green in outer part, of radiating, branched and anastomosing hyphae; epithecium scarcely differentiated from the hymenium; hymenium 60-70 μm high, colourless but often with greenish vertical streaks in lower part, dark aeruginose green in upper part, the pigmented parts K-, N+ purple; paraphyses numerous, 1-1.8 μm thick at mid-level, simple or sparingly branched in upper part, the apical cells to 3 μm wide; hypothecium olivaceous or pale brown in upper part, colourless in lower part, up to 380 μm high. Asci 8-spored, clavate to cylindrical-clavate, with an unstained wall and a K/I+ blue outer layer and apical dome, the latter with a non-amyloid, cylindrical axial mass. Ascospores (0-)1-3-septate, hyaline, fusiform, straight or slightly curved, 13-22(-24) x 3.5-5 μm. Pycnidia more or less immersed, the wall green (K-) in upper parts. Mesoconidia cylindrical to oblong-ellipsoid, sometimes slightly constricted in the middle, 4-7 x 1.2-2 μm. Photobiont micareoid, the cells 4-7 μm wide. Spot tests: thallus and apothecial sections K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: an arctic-alpine species growing on plant remains and siliceous rocks near and above treeline; the Italian sample was collected by Lojka between Paneveggio and Predazzo, on a porphyric boulder.