Massariosphaeria mosana  

Anamorph: not known.
Teleomorph: ascostromata perithecial, 200-400 µm diam., globose to pyriform, sometimes papillate, the surrounding substrate stained purple-red. Peridium to 60 µm thick (possibly more), composed of dark thick-walled angular cells; ostiolar region circular in transverse section, lined with periphyses. Interascal tissue composed of numerous, branched and septate pseudoparaphyses, ca 2 µm diam. Asci 115-165 x 18-27 µm, clavate, short-stalked, 8-spored. Ascospores bi- or triseriately arranged, 30-52 x 8-11 µm, fusiform to clavate-fusiform, often slightly curved, yellow-brown to red-brown, finely punctate, 7- to 10-septate, the cell immediately above the primary septum longer and slightly inflated, constricted at most septa, without longitudinal and oblique septa, with a gelatinous sheath that is sometimes not visible at maturity.