Thallus 2-6 cm diam., mono- or polyphyllous, membranaceous, thin, crisp, fragile, very irregular in outline, rosette-forming to orbicular to deeply and complexly incised, umbo not prominent. Lobes rounded or imbricate, margins occasionally lacerate, fenestrate, curled under or reflexed. Upper surface smooth, glossy, rough or cracked peripherally, or weakly wrinkled or squamulose, dull to shining, buff brown to dark brown or blackish. Lower surface smooth to areolate, bullate, uniformly charcoal black, umbilicus small, rarely divided, rhizines absent. Apothecia rare, scattered, mostly peripheral, sessile, irregular, disc black, convex, with few, thin gyrae. Ascospores colourless, ellipsoid to irregular, 12-18 × 3.5-7 µm.