Anamorph: not known. Teleomorph: ascomata perithecial, 70–120 μm diam., black, subglobose, scattered but often abundant, immersed but becoming erumpent in the ostiolar zone. Vegetative hyphae 1–3 μm diam., immersed, brownish, septate, branched, thin-walled. Peridium brown, 8–10 μm thick, composed of several layers of polygonal cells 4–8 μm diam., externally with a thin, dark wall, internally hyaline, lower part covered with numerous elongate vegetative hyphae. Hymenium I+ red, KI+ blue (especially in the basal parts). Interascal tissue absent, periphyses short, simple to 1-septate, 2–3 μm diam. Asci 50–60 × 9–13 μm, obclavate, the wall thickened in the apical part, fissitunicate, not staining in iodine, (6–) 8-spored. Ascospores biseriately arranged, (11–)12–15(–16) × 4–5 μm, ellipsoidal with obtuse apices, soon light grey to brownish inside the asci, (2–) 3-septate, the septa very thin and sometimes with a small torus, not or slightly constricted at the septa, with many small oil guttules, without a perispore or gelatinous sheath.