Can. J. Bot. 49: 876, 1971

Ascomata 120-205 mm in diameter, globose or subglobose, superficial, non-ostiolate, coriaceous, irregularly dehiscing, dark brown to black, Peridium semitransparent, composed of three or four layers of irregular or angular, thin-walled cells. Paraphyses up to 12 mm in diameter, composed of vesicular cells, early deliquescing.

Asci 84-120 x 12-17.5 mm, eight-spored, thin walled, clavate, broadest in the middle, short pedunculate, apically truncate, unitunicate, deliquescing, with a simple apical ring.

Ascospores biseriate, ellipsoidal, becoming one-septate in the lower third, slightly constricted at the septum; large upper cell 16-25 x 12-15 mm, ellipsoidal, apex conical or umbonate, base truncate, olivaceous to brown, thin-walled, smooth, with a subapical germ pore, 1 mm in diameter, lower cell small, 4.3-6.8 x 4.5-6.5mm, broadly cylindrical, apex truncate, base broadly rounded, hyaline.