Thallus ± linear-elongate, spreading, loosely attached, to 20 cm diam. Lobes linear-elongate to 6 mm wide, ± discrete, to contiguous, margins rather fragile, copiously incised, isidiate, ± ascending, becoming concave and ± canaliculate. Upper surface bright lettuce-green when wet, pale greenish-grey or fawn when dry, undulate, ± canaliculate, wrinkled to shallowly faveolate, matt or shining, marginally and then laminally isidiate. Isidia terete to somewhat flattened, simple, becoming coralloid-branched, fragile and easily abraded, leaving small, white pock-like depressions not to be confused with pseudocyphellae. Medulla white. Photobiont green. Lower surface pale pinkish-buff, whitish at margins, obscurely wrinkled-scrobiculate, bullate, glabrous, rarely very thinly and patchily tomentose centrally, tomentum white, silky, often lacking. Pseudocyphellae white, minute, inapparent, punctiform, fleck-like, numerous. Apothecia sparse, submarginal, 1.0-1.8 mm diam., subpedicellate, disc red-brown, matt or shining, concave to plane, margins denticulate-isidiate, thin, concolorous with thallus, thalline exciple wrinkled. Ascospores brown, fusiform, 1-3-septate, (23-)28-34(-42) × 7-11 µm. Chemistry: 7β-acetoxyhopan-22-ol, hopane-15α,22-diol, methylgyrophorate (tr.) and gyrophoric acid (C+ red).