Thallus orbicular, ± rosette-shaped to spreading or straggling, 5-8(-12) cm diam., ± centrally attached, margins often free. Lobes linear, somewhat elongate, margins irregularly incised, ± ragged, granular-sorediate, not phyllidiate or isidiate. Upper surface bright lettuce-green when wet, greyish-green to buff-pink when dry becoming suffused reddish on storage, ± scabrid at margins, smooth, undulate to ± faveolate-impressed centrally, ± silky white-tomentose, ± sorediate. Soredia marginal in linear to sublinear soralia, or laminal in scattered, punctiform to confluent soralia, granular, yellow. Medulla yellow. Photobiont green. Lower surface pale yellow, ± evenly white, silky tomentose to margins. Pseudocyphellae yellow, prominent, numerous, flat, to 1.5 mm diam.Apothecia rather rare, pedicellate, disc dark brown or red-brown, concave to plane, somewhat undulate, matt, epruinose, margins eroded, granular-sorediate, exciple corrugate-scabrid, concolorous with thallus, ridges often yellow-sorediate. Ascospores brown, oblong-ellipsoid to obtusely fusiform, 3-septate, 28-30 × 10-13 µm. Chemistry: Pulvinic acid, pulvinic dilactone, calycin, and a complex mixture (c. 12) of lupane triterpenoids (Dr A.L. Wilkins pers. comm.).