Thallus crustose, slightly placodioid, 2-5 cm in diameter, formed of tight, short and stocky lobes, slightly convex or domed, upper surface strongly pruinose, dirty whitish, pale greyish white. Apothecia more or less numerous, sessile, 0.5-1 mm in diameter, flat disc, pruinose, brownish, pale pinkish-brown, greyish-brown, margin thick, more or less smooth, pruinose, whitish. Spores elliptical, hyaline, 8-13 x 4-7 µm. Photobiont: chlorococcoid. Thallus: C + orange, K + pale yellow, KC + orange, P-, UV + orange. Mediterranean species, occur on limestone rocks or walls of limestone or become alkaline, cement.
