Anamorph: germinating ascospores sometimes produce conidia directly, but otherwise unknown. Teleomorph. Ascomata (400–) 500–650 µm diam. and 500–700 µm tall, in extensive clusters (frequently colonizing cut ends of wood), superficial, subglobose to broadly ovoid , ± smooth. Neck hardly papillate, not sulcate. Peridium shining black, 35–45 µm thick, composed of two layers; the outer layer of dark brown, thick-walled angular cells 15–20 µm diam. and covered with a single layer of colourless cells, giving a glossy appearance in fresh material, and the inner layer of colourless to yellowish elongate cells. Periphyses 15–20 × ca 2 µm, colourless, thin-walled, septate, rounded at the tip. Interascal tissue composed of tapering unbranched thin-walled paraphyses 3–5 µm diam., longer than the asci, immersed in a colourless mucous matrix and sometimes deliquescing at maturity of the ascoma. Asci (100–) 120–150 × 9–11 µm, cylindrical, not fissitunicate, the basal part tapered and 30–50 µm in length, the apex slightly attenuated, broadly rounded to truncate and somewhat thicker-walled, with a refractive ring 3·5–5 × ca 0·5 µm, not blueing in iodine, 8-spored. Ascospores arranged biseriately or in fascicles, 19–25 × 3–5 µm, colourless and one-celled, sometimes eventually becoming pale to yellow-brown, cylindrical, straight, arcuate or sigmoid, the lower 20–25% bent obliquely and not attenuated at the base, hardly tapered toward the rounded apex, without cellular or gelatinous appendages.