Description: Thallus crustose, episubstratic, rust-red, rimose or rimose-areolate, the areoles convex, matt, without a distinct prothallus. Apothecia 0.2-0.4 mm across, at first immersed, then sessile and more or less constricted at base, with a concave to flat, pale brown to reddish brown disc, a darker, thick, prominent, often radially striate proper margin, and a thin, finally often excluded thalline margin. Epithecium pale brown, N-, inspersed with brown to black granules not dissolving in K; hymenium colourless or pale yellow, 160-180 µm high, I+ blue; paraphyses rather lax, simple or sparingly branched and submoniliform in upper part, 1.5-2 µm thick, the apical cells not swollen; hypothecium colourless. Asci 8-spored, cylindrical-clavate, the outer wall K/I+ blue, but the inner walls and apical dome K/I-. Ascospores 1-celled, hyaline broadly ellipsoid to subglobose, (12-)17-26 x (6-)10-13 µm. Photobiont chlorococcoid (Asterochloris), the cells <15 µm wide. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: recently found in the Alps, this mainly northern lichen should be looked for more intensively on iron-containing siliceous rocks.