Thallus ± orbicular to spreading, loosely attached, or sometimes closely attached, 5-8(-12) cm diam. Lobes whitish-grey to leaden grey when dry, darker bluish-grey when wet, 0.3-0.6(-1) cm wide, adjacent often imbricate, broadly cuneate to flabellate, apices rounded, margins entire or occasionally minutely notched or incised, ± deflexed. Upper surface smooth or minutely wrinkled, rather coriaceous, matt, without isidia, usually with transverse, concentric ridges, often with regenerating lobules in older parts of the thallus. Lower surface usually pale but sometimes dark, with a dense felt of rhizines usually arranged in concentric lines. Rhizines whitish, often turning bluish or entirely black, usually not projecting beyond lobe margins. Apothecia ± frequent, to 2 mm diam., disc concave when young, becoming plane or rarely slightly convex when old, reddish-brown, sometimes blackened, with a double margin, proper margin prominent in young apothecia, rising above the disc, visible in old apothecia only as a pale or rarely dark line, or completely occluded by thalline margin, thalline margin crenulate, or ± fused, small flattened lobules arising from base of the apothecia. Ascospores 11-15 × 6-8 µm.