Anamorph: not known. Teleomorph: stromata 0.8-2 (-2.5) mm diam., irregular in shape, subepidermal, containing (4-) 8-30 ascomata, grey-brown in surface view, slightly raising the substrate surface and with very shallowly domed ascomata, the ostioles usually inconspicuous and hardly more strongly pigmented. Stromata 150-280 µm deep, irregular due to growth between the vascular bundles of the host, very strongly melanized and ± black in section, composed of dark brown fairly thick-walled globose cells 6-11 µm diam.
Ascomata perithecia, 140-170 µm diam. and 150-180 µm tall, ± globose to slightly oblate, the inner wall of the ostiolar region conical. Peridium composed of 8-12 layers of strongly flattened cells to 15 µm diam., with dark brown walls, the pigmentation gradually becoming less pronounced towards the fertile cavity with the inner layers ± hyaline, similar in thickness all around the perithecium. Interascal tissue composed of copious unbranched gradually tapering thin-walled paraphyses 3-3.5 µm diam. near the base and ca 2 µm diam. near the apex, not surrounded by a gel layer. Ostiolar region lined with narrow periphyses 10-15 x ca 1 µm in size. Asci (61-) 65-77 x 6-8 µm, cylindrical, with a fairly short tapering stalk, the apex rounded, fairly thick-walled but not fissitunicate, with an inconspicuous subapical ring ca 2 µm diam. and 0.5 µm thick, not blueing in iodine, the ascus cytoplasm weakly dextrinoid, 8-spored. Ascospores arranged obliquely uniseriately, 8.5-9.5 (-10) x (3-) 3.5-4 µm, ellipsoidal to cylindric-ellipsoidal, rarely slightly ovoid, hyaline, aseptate, thin- and smooth-walled, usually containing two large oil bodies which can make the spore appear septate, with an inconspicuous narrow gelatinous sheath.