Thallus crustose, spreading in irregular patches, 2-8(-10) cm diam., pale olive greenish, yellowish-fawn, pale yellow or grey-yellow to glaucous brown, nodular-papillate in humps or concrescent lumps, 0.3-1.2 mm diam., ± glebose, minutely white-papillate, thick, shining or dull. Perithecia often densely crowded in prominent hemispherical thalline verrucae, monocarpic, 0.4-1.5 mm diam., apical pore black, indented to 0.2 or 0.3 mm diam. Excipulum carbonised, red-brown. Paraphyses colourless, branched-reticulate. Ascospores very large 1, occasionally 2 per ascus, encased inside a gelatinous sac which is extruded with the ascospores, which becomes dark red-brown with age, densely muriform, wall of two distinct layers, 230-330 mm × 60-90 µm.