Thallus foliose, rather thin, crisped at margins, varying from umbilicate to ± short-stalked, 1-2 cm diam., stalk 0-2 mm diam., and of variable height, from which radiate flat folioles, pale to dark olive-greenish, translucent. Photobiont , a single layer of cells in tetrads with the long axis of the cell perpendicular to the surface of the gel at the margins, inside which the elongate cells form two pairs of tetrads, the cells disappearing and becoming increasingly irregularly arranged towards the stalk where tetrads are rarely seen. Lower surface with rhizines near stalk, smooth elsewhere. Ascocarps immersed near stalk, spherical, to 3 mm diam. Ascospores elongate-ellipsoid to cylindrical or rarely fusiform with rounded ends, (8.5-)11-17.5(-18.5) × 3-5 µm. Pycnidia 160-250 µm diam., similar to ascocarps, subglobose to lentiform, immersed, irregularly chambered, ostiolate, epapillate, coriaceous, top and base brown, sides hyaline, solitary or gregarious. Conidia 2 × 1 µm, subglobose or ellipsoid, simple, hyaline.