Fruiting body urn to goblet shaped; apothecia 0.5-1.5 cm broad, deeply cupulate, not expanding; margin pallid, crenate, incurved to upturned; fertile surface dull orange-brown to reddish-brown, glabrous; external surface glabrous, dull-brown, fading to pale-buff; stipe 0.3-1.0 cm long, 1.0-2.0 mm thick, straight to curved, the surface dull-brown covered with a white tomentum.
Spores 13.5-18.5 x 6.0-9.5 µm, ellipsoid, some narrowly so, a few oblong, smooth, thin-walled, eguttulate, contents granular; spore deposit not seen.
Gregarious to densely clustered on burnt soil or in campfire pits; fruiting during the spring in the Sierra Nevada and presumably also the coast ranges.
Ediblility unknown; insignificant.
A distinctive goblet shape, crenate cup margin, and habit of growing in burned soil are hallmarks of this attractive Ascomycete. It often fruits in vast numbers along with other fire-associated cup fungi like Pyronema omphalodes, Peziza violacea, P. pratervisa, Anthracobia macrocystis, and Plicaria endocarpoides. Geopyxis vulcanalis differs in growing in soil (not burnt) under conifers, being more urn-shaped, with a yellowish fertile surface.