Thallus 2-3 (-5) cm diam., initially developing as a single shallowly vase- or trumpet-shaped structure with revolute margins (appearing like a mushroom), often with a distinct stipe, eventually developing several irregular to suborbicular overlapping lobes, leathery but often brittle when dry, when old often with a crenate to lacerate margin. Upper surface smooth to mildly scrobiculate, greyish to dark brown (in wet or dry conditions), matt or slightly glossy. Cilia usually absent, sometimes present on small or regenerating lobes, simple, white, to 500 µm in length. Isidia always present, abundant, laminal, first simple and globose or with a flattened top, eventually forming upright coralloid masses to 200 µm high, sometimes with substipitate lobules on old thalli, similarly coloured or darker than the thallus. Lower surface smooth to scrobiculate, sometimes strongly so, pale orange to brownish, darker towards the center on old thalli, sparsely to densely tomentose the hairs fasciculate, especially towards the centre. Cyphellae usually abundant, round or angular, urceolate with a wide pore, erumpent to prominent, the margin elevated and involute, whitish to cream-colored, rarely brownish, 400-600 µm diam., the surface cells papillate, the papillae 4-6 (-8) per cell, 1-2 µm diam. Photobiont Nostoc. Anamorph: not known. Teleomorph: not known.