Thallus areolate, up to 5 cm diam.; hypothallus well developed, black; areolae up to 0.5 mm diam., medium grey to medium brown, dull, scattered to contiguous, round or partly angular, moderately to strongly convex; medulla KI–. – Apothecia up to 0.6 mm diam., black, epruinose, more or less orbicular, weakly to strongly convex, with a thin and more or less disappearing margin; excipulum dark reddish brown in the rim, pale brown the inner part, K+ red; hypothecium dark brown, K–; hymenium colourless; epihymenium green, K–; no crystals in the apothecium; ascospores 8 per ascus, eumuriform, persistently colorless, 32–42 × 14–20 µm. – Conidiomata not seen.
No lichen substances or an undetermined fatty acid; spot tests: PD–, K–, C–.
On exposed siliceous rock, often near lakes in the lowlands. Rarely collected.
The species is recognized by the convex, gray to brown areoles, the eight hyaline, eumuriform ascospores, the green epihymenium, and by the lack of crystals in the apothecium.