Thallus effuse, sometimes partly endophloeodal, endoxylic or endocuticular (on bryophytes), developed on surface of substrate as subconvex, ± contiguous rounded areolae, or sometimes forming an uneven crust or developing into discrete, scattered or contiguous, smooth granules c. 40-200 µm diam., greenish-white, grey-white to blue-grey, more rarely dark grey. Granules often darkened on their outer; exposed surface, greenish-white below. Thalline areolae and granules ecorticate, but surrounded by a thin, hyaline amorphous layer c. 2-5 µm thick, hyphal walls in outer 10 µm of thallus often with a grey-green to blue-green pigment (HNO3 ± red or red-violet). Apothecia scattered to crowded, often contiguous, adnate, plane to convex sometimes tuberculate, sometimes with an indistinct margin level with disc, pale lead-grey to grey-black or black, sometimes grey-brown, or whitish or ivory in shade forms, whitish or paler at margins (0.12-)0.14-0.4(-0.6) mm diam., to 1.0 mm when tuberculate. Disc finely roughened, matt or slightly glossy (when black) margin when apparent smooth and often more glossy than disc. Hymenium 40-55 µm tall, olive or blue green (HNO3 ± red in upper part, epithecium), in dark-coloured fruits green pigment in gel matrix and walls of paraphyses. Asci clavate 40-55 × 14-17 µm. Ascospores fusiform or clavate-fusiform, often somewhat curved 1-3-5-septate, (11-)15-23(-24) × 3-5(-6) µm. Paraphyses branched, entangled above forming an epithecium, 1-1.5 µm thick, apices to 2.5 µm thick, coloured with green pigment. Hypothecium hyaline or straw-coloured, 40-70 µm thick, of densely interwoven hyphae. Exciple hyaline or pale straw-brown in part, of radiating branched hyphae c. 1-1.5 µm thick in a gel matrix, ± dissolving in K, I-. Pycnidia ± frequent, of two types: (1) innate, white 140-200 µm diam, with gaping ostioles with macroconidia strongly curved or sigmoid, non-septate (19-)21-40(-50) × 1-1.5 µm: (2) ± sessile white, 60-80 µm diam., with slightly gaping ostioles with microconidia, straight, narrowly fusiform (5-)6-7(-7.7) × 0.4-0.7 µm. Chemistry: Thallus and apothecia C+ red, K-, Pd-. Gyrophoric acid.