Thallus 1.5-4(-6) cm diam., mono- or polyphyllous, ± rosette-forming to rather irregular, undulating to convolute, or ± plicate-subfaveolate in parts, margins incised-ragged, ± copiously rhizinate, rhizines coralloid. Upper surface dull, pale grey-white, dark grey, brownish-grey or buff, ± white-pruinose to scabrid-areolate or granular-verrucose, rhizinate, rhizines black or grey-black, coralloid, with numerous, dark thallospores. Lower surface dull to minutely scabrid-areolate, lacunose, bullate to uneven-undulate, pale buff to brown-grey, sparsely to densely rhizinate. Rhizines coralloid, best developed towards margins. Apothecia scattered, few to ± numerous, pedicellate, 0.2-2.0 mm diam., convex, convolute, distinctly gyrose, black, epruinose.