Thallus a basidiocarp, sessile or bent backwards, single or united in rosettes, soft or paper-like, small or to 25 cm diam. Upper surface glabrous or hairy or radially fibrillose, sometimes furrowed or zonate, greyish or some shade of green or bluish-green or olivaceous. Lower surface even, granular, reticulate or with low, concentric bands of whitish or cream fruiting bodies (hymenophores). Photobiont green (), or blue-green (). Basidia in fascicles, clavate or subcylindrical with 4 curved slender sterigmata. Basidiospores subcylindrical, narrowly ellipsoid 6-10 × 2.8-5 µm, thin-walled, colourless.