Apothecia with the pileus inflated, generally wavy to cerebriform, to 3-9 cm broad and high; on a stipe ca 2.3 cm thick and 5 cm long, when fresh white, translucent, hollow and stuffed at the base with white, cottony mycelium. Hymenial surface yellow-brown (7.5YR4/4), covering folds which often extend down around the stipe and fuse with the stipe at some points. Tissue of the pileus white, when fresh rubbery-brittle, 1-2 mm thick, of textura intricata; the hyphae hyaline, thin-walled, septate, 5-16 µm in diam. Paraphyses slenderly clavate to cylindrical, mostly 7.5-8(-9.8) µm broad at the apex, gradually tapering to 5-5.4 µm about 50 µm below apex, septate at a point 60-85 µm below apex and branched about 50 µm further down. Asci, when fresh, 470-485 × 16-19 µm, essentially cylindrical, not bluing in Melzer’s reagent. Ascospores fusoid to broadly ellipsoid, some flattened on one side, (23-)24-27.5(-31) x (9-)11-12.5(-13.5) µm excluding appendages and measured from mounts in Melzer’s; epispore continuous, generally wrinkled, up to 1 µm thick except for the apex where thickened to 2.5 µm to form a truncated appendage, bluing in cotton-blue.
Substrate: Soil, duff, well-rotted wood and old logs, stumps, etc. of hardwoods, particularly Betula spp.
Distribution: Quebec, Ontario