Ascostromata perithecia, 150-250 µm diam., pyriform, sometimes with a flattened apex, scattered on the host thallus and then ± immersed, also in apothecia where they are usually somewhat smaller and often ± erumpent to almost superficial, black, with a broad periphysate ostiole. Peridium chestnut brown, 15-20 µm thick at the base and to ca 40 µm thick in the ostiolar region, composed of irregular ± globose dark brown cells. Interascal tissue of very dense strongly anastomosing narrow pseudoparaphyses ca 1.5 µm diam. Asci 70-100 x 12-15 µm, cylindrical to cylindric-clavate, fissitunicate with a large well-developed ocular chamber, mostly 6-spored, rarely with 8 or 4 spores. Ascospores arranged biseriately, (15-) 16-20 (-21) x 5.5-8.5 (-9) µm, clavate to clavate-ellipsoidal, the ends rounded, strongly constricted at the slightly submedian section and with the upper cell distinctly wider than the lower, hyaline, fairly thick-walled, hyaline but with a perispore that breaks down to form small brown warts when over-mature.
Description adapted from Grube & Hafellner (1990).