Stromata 5-15 mm diam, applanate, discoid to irregular and wide-spreading, to 1 mm thick, with distinct, sometimes slightly raised brownish margins. Surface sometimes exhibiting cracking similar to that found in Diatrype stigma, dull black and sometimes grey-pruinose, with sunken grey ostioles producing an overall dark greyish appearance, interior dull black. Anamorph: Nodulisporium-like. Teleomorph: ascomata perithecia, 200-400 µm diam. and 300-500 µm tall, ovoid to almost pyriform, the walls thin and delicate. Ostioles umbilicate, seated in grey depressed areas. Interascal tissue of copious fairly thin-walled unbranched paraphyses. Asci cylindric, the sporing part 103-118 x 8-11 µm with stipe 7-30 µm long, apical apparatus blueing in iodine, plate-like to almost cuboid, 3-3.5 µm broad x 1.5-3 µm high. Ascospores arranged uniseriately, (13 )14-18(-19) µm x 7-9(-10) µm, ellipsoidal to ellipsoidinaequilateral to obovoid, unequally two-celled, the larger cell 10-13 µm long and the smaller cell 5-7 µm long x 4-7 µm broad, the larger cell sometimes dark brown to almost black and the smaller cell hyaline to subhyaline but most commonly both cells remaining hyaline, smooth, without a gelatinous sheath or appendages. Larger cell when pigmented with a straight full-length germ slit, not apparent when hyaline; the smaller cell without a germ slit.