The fungus forms hard, brittle, hemispherical bodies (= stromata) 0.5-1.5 cm across. Stromata are solitary or clustered and occur in groups of dozens or even hundreds. They are dull brick-red to black, with a pimpled surface (seen easily with hand lens). Pimples are the mouths of tiny ovoid perithecia embedded in the stroma . Common on the bark of dead beech.