Teleomorph: ascomata perithecia, 200–280 x 200–250 μm, pyriform or subglobose, black, rather thick-walled, immersed in the host thallus with the ostiolar region protruding. Ascomatal wall 25–35 μm thick at the base, narrower near the ostiole, the exposed part darker, composed of 4-6 layers of angular flattened cells 8–13 x 4–6 μm in size. Interascal tissue of paraphyses 4–6 μm diam, becoming evanescent before the asci mature, and with simple periphyses ca 20 x 1,5–2 μm in size. Asci ca 90 x 13–19 μm, cylindric-clavate, (6-)8-spored. Ascospores (13–) 15–20 x 8–10 (–11) μm, hyaline, 1-septate, very rarely aseptate, cylindric-ellipsoidal, the ends rounded, slightly to strongly constricted at the septum, fairly thin-walled, smooth, without a gelatinous sheath or appendages.