Thallus usually covering surface, ecorticate, granular-verrucose, pale whitish grey to pale green, often with yellow to rusty reddish patches which may extend over most of the thallus, rarely immersed. Photobiont Trebouxia. Anamorph: not known. Teleomorph: mazaedia apothecia, 0.4-2 mm tall, 5-15 times as long as width of stalk; stalk 70-150 µm diam., shiny, black, without pruina; fertile head broadly to narrowly obconical. True exciple well-developed, without pruina. Ascospore mass pale to dark brown, often with a yellow tinge. Asci cylindrical to narrowly clavate, thin-walled and evanescent, developing within copious hypha-like paraphyses. Ascospores uniseriately to biseriately arranged, 5.5-7.5 μm diam., globose, aseptate, dark brown, thick-walled, when mature coarsely and irregularly fissured. Chemistry: yellow-red, quinonoid pigment in thallus, K+ deep red; ascospore mass with yellowish K+ red pigment.