Anamorph: mycelium immersed, pale brown to hyaline, branched, 3.5-4.5 um diam. Conidiomata acervular, erumpent, forming blisters on the bark, partly immersed, shining black, spherical to pulvinate, to 3 mm diam. and 0.5 mm deep, separate or confluent, the wall composed of several layers of dark brown thick-walled hyphal tissue, dehiscence irregular. Conidiophores 17-45 um x 3-7.5 μm, cylindrical, rarely inflated along their length, 0- to 2-septate, hyaline to pale or dark brown, smooth, straight or often flexuous, formed from the upper cells of the conidomata. Conidiogenous cells 7-25 X 3.5-7.5 μm, not differentiated morphologically from the conidiophore, smooth, hyaline, pale to dark brown, cylindrical, straight or slightly curved, with 1-2 percurrent proliferations. Conidia (34–)38–46(–55) × (10.5–)11.7–14(–15) μm, cylindrical, cylindric-ovoid, or cylindric-ellipsoidal, dark brown, 3- to 4-euseptate, smooth, straight or slightly curved, guttulate, rarely constricted at septa, apex obtuse, base truncate, with a hyaline sheath 1–1.5 μm thick that sometimes degenerates into minute marginal frills. Paraphyses hyaline, filiform, cylindrical, septate, to 110 μm long and 2-3 μm wide. Teleomorph: stromata ca 1–10 mm diam, inconspicuous, immersed in bark, lifting it and causing fissures, pale yellowish, ochre, brown to olive brown in section, containing up to 80 perithecia. Ectostroma inconspicuous, limited to a brownish disc of a gel matrix containing numerous, tightly packed periphyses extending from the ostioles. Ostioles inconspicuous and often invisible at the surface, cylindrical, with pale brownish walls, convergent in groups, not projecting. Entostroma an inconspicuous loose network of hyaline to brownish hyphae (1.5–)2–4(–6) μm diam., enclosing groups of usually tightly packed ascomata disposed in a valsoid ring. Ascomata perithecia, (400–)500–600(–700) μm diam., depressed globose to lenticular, dark brown to nearly black when mature. Peridium of dark brown angular cells. Asci (185–)190–240 (–275) × (23–)26–30(–33) μm, clavate to ellipsoidal, thick-walled, the apex without a refractive ring, sessile, evanescent at the base, 8-spored. Ascospores (31.5–)35–42(–49) × (11–)12–14(–17) μm, dark brown, ellipsoidal to cylindrical, with usually 3 eusepta, multiguttulate, with subglobose to ellipsoidal appendages at both ends projecting for (3.5–)4.5–7(–8) μm and (9–)10.5–13(–14) μm wide.