Protothelenella santessonii  

Anamorph: not known.

Teleomorph: stromata absent. Ascomata perithecia, 100-200 µm diam., ovoid to subpyriform, black, scattered, semi-immersed in the host thallus, the wall dark brown and thick above, paler and thinner at the base. Interascal tissue of filiform pseudoparaphyses. Asci ± cylindrical, 8-spored. Ascospores 18-24 x 10-12 µm, ellipsoidal, hyaline, submuriform with 3-5 tranverse septa and a single longitudinal septum that sometimes does not extend to the apices.