Anamorph: not known. Teleomorph: ascomata perithecial, arising singly, rarely confluent, scattered on creamy or whitish patches of bark, sharply delimited only where juxtaposed to other species when a purplish-black marginal line to 50 µm wide sometimes develops; immersed, the outer peridermal layers raised to form low hemispherical projections. Individual ascomata dimidiate, 200-300 (-400) µm diam, 90-125 µm tall, black, shiny, the basal fringe poorly developed and rarely more than 25 µm broad, ostiole depressed or ± plane. Involucrellum dark reddish brown, becoming olivaceous green in KOH, 25-40 µm thick, consisting of periderm cells intermixed with fungal hyphae. Peridium 10-15 µm thick, composed of a few irregular layers of brown, often unevenly thickened hyphae; base of ascoma similar in structure to the upper parts of the ascomata, very variable in development, uneven, ± absent to 20 µm thick. Centrum not turning blue in iodine. Interascal tissue of cellular pseudoparaphyses, persistent, branched and anastomosing, septate, 1-5-2 µm diam. Asci arising from the base of the ascomatal cavity, ± vertically orientated or inclined towards the ostiole, 55-70 x 12-18 µm, elongate-clavate, short-stalked, fissitunicate, with an internal apical beak, 8-spored. Ascospores biseriately arranged, (15.5-) 17.5-21 (-25) x (6-) 7-9 (-10) µm, clavate-ellipsoidal, 1-septate, constricted at the septum, the lower cell usually narrower but either shorter or longer than the upper, the upper cell generally rounded, the lower generally attenuated and sometimes constricted along its length, olivaceous brown, often guttulate (fresh material), delicately verruculose, with a thin gelatinous sheath swelling to 2 µm (exceptionally more) in KOH.