Thallus crustose, epi- or endophloeodal, effuse or lacking, matt or glossy, olive-green or pale yellowish-brown, to scarcely differentiated from substrate, often with scattered, minute white spots (×10 lens), not, or rarely, delimited by a thin, black marginal line. Photobiont green, , in a ± continuous subcortical layer. Ascocarps in the form of perithecia, single to 2-5 confluent, embedded in a carbonaceous stromatic shell (involucrellum). Perithecial wall (exciple) internal to involucrellum, brownish or yellowish. Ostioles single or joined, inclined, or vertical, apices punctate, black, pale whitish or reddish. Paraphyses persistent c. 1 µm thick, septate, net-like, anastomosing. Asci bitunicate, clavate, thick-walled. Ascospores (4-)8 per ascus, broadly ellipsoid, brown at maturity, muriform.