Can. J. Bot. 64: 3036-3042, 1986.

Ascomata 570-800 mm high, 750-1150 mm in diameter, conical with a flat base, erumpent from the substrate and superficial when mature, seated on a thin stroma, ostiolate, periphysate, epapillate, carbonaceous, black, with irregular bulges or ridges around the ostiole, gregarious, single or sometimes two or more attached to each other. Pseudoparaphyses trabeculate, septate.

Asci 300-420 x 22-30 mm, eight-spored, cylindrical, pedunculate, thick-walled, fissitunicate, with a refractive apical ring or cap, arising from a basal ascogenous tissue, composed of small cells.

Ascospores 50-65 x 15-20 mm, overlapping nonstichously in the ascus, ellipsoidal, initially one-septate and later becoming three-septate, constricted at the central primary septum, hyaline, surrounded by a gelatinous evanescent sheath.