Summary:
Features include 1) irregularly convex or saddle-shaped or lobed cap that is medium brown to dark brown on the upper side, white or creamy or pale gray-brown and strongly ribbed on the downy underside, 2) stem that is whitish usually with wine red tints, deeply ribbed, and downy, 3) growth on rotted hardwood in late spring and summer, and 4) round spores with one droplet but without apiculi. The description is derived from Abbott(1). The online Species Fungorum, accessed June 1, 2014, gives Pseudorhizina sphaerospora (Peck) Pouzar as the current name, but the molecular study of Methven(4) nests it among Gyromitra species.

Microscopic:
spores 8.5-10.3 microns in diameter, round, smooth, colorless, with one oil droplet, one de Bary bubble in most spores at maturity; asci 100-150 x 10-16.3 microns; paraphyses 4-7.5 microns wide at tip, narrowly clavate, expanded gradually to tip, "brown in mass, contents finely granular", (Abbott)

Notes:
Gyromitra sphaerospora is normally eastern and midwestern in North America, but has been found in BC near Prince George (Nancy Smith-Weber, pers. comm.). Collections were examined from AB, MB, SK, Poland, and the species has been reported from MT, Europe, and Asia, (Abbott).

Synonyms and Alternate Names:
Neoantrodia serialis (Fr.) Audet
Polyporus serialis Fr.