Thallus squamulose, closely attached, irregularly spreading 4-8(-10) cm diam. Squamules minute, scattered at margins, 0.5-1.0 mm diam., round to irregular, coalescing centrally into a ± dense, flat, appressed mosaic, often microphylline or sublobulate, often diffract-areolate centrally, ± continuous, convex, plane or concave, jigsaw-like. Prothallus black, byssoid, thick and fibrous or thin, to 5 mm beyond marginal squamules. Upper surface pale greenish or yellow- green, margins not or rarely white-frosted, glossy, waxy, smooth, ± shining, without pruina or tomentum or crystals. Cephalodia infrequent, occasionally larger than squamules, flattened, to 1 mm diam., placodioid, very shallowly wrinkled-plicate, smooth, shining, pale bluish-grey when wet, or in small, flattened globules 0.1 mm wide, occasionally laminal, normally marginal or between squamules, sometimes striate, purplish to brown. Apothecia sessile, round to irregular, 0.5-2.5 mm diam., disc red-brown, matt, not pruinose, convex to plane, sometimes contorted, etched, or confluent-convolute with thalline lobules, margins relatively thick, inflexed, crenulate-striate, wavy, thalline exciple areolate. Ascospores 13-22 × 9-11 µm.