Thallus areolate, up to 5 cm diam.; hypothallus well developed, black; areolae up to 0.8 mm diam., pale grey to medium brown, dull, scattered to contiguous, more or less angular, plane to weakly convex; medulla KI–. – Apothecia up to 1 mm diam., black, epruinose, orbicular to angular, weakly concave to weakly convex, often umbonate or gyrose, with a narrow and persistent margin; excipulum dark reddish brown in the rim, paler brown in the inner part, lacking crystals, K+ red; hypothecium brown, K–; hymenium colourless; epihymenium usually with a mixture of dark reddish brown and dark green pigments, sometimes containing crystals dissolving in K, brown pigment K+ faintly red (green parts turning more brightly green); ascospores 8 per ascus, submuriform or partly 3-septate, soon becoming dark green or brown, 17–29 × 8–13 µm. – Conidiomata not seen.
No lichen substances or more rarely stictic acid; spot tests: medulla PD– or PD+ orange, K– or K+ yellow, C–.
On more or less iron-rich rock in sun-exposed localities. Sparingly collected.