Truffle Genus: Geopora

Geopora cooperi ascospore

Kingdom: Fungi Phylum: Ascomycota Order: Pezizales Family: Pyonemataceae

Spore Characters

Although Geopora, Balsamia, and Barssia can be distinguished by spores alone, detailed knowledge of each genus is required to do so. In practice, it is rarely important to distinguish them. The more ecologically significant difference, between smooth-spored hypogeous vs. epigeous Ascomycotina, cannot be resolved on the basis of spore characters alone. Our experience plus the literature as reviewed by Fogel and Trappe (1978) suggest that epigeous Ascomycota are rarely eaten by mammals. Until this conclusion is refuted by better evidence, we assume that nearly all ascospores in animal digestive tracts are of hypogeous species.

View photos of Geopora spores

Sporocarp Characters

Shape and Size: Subglobose to cerebriform, 1-7 (-10) cm in diameter.
Peridium: Brown, tomentose.
Gleba: Most species are hollow and subsphaerical with an opening at the soil surface. Only two are sequestrate; G. cooperi has a much infolded and convoluted gleba. G. clausa usually has a single, open chamber.
Odor: Fungoid to radish-like

View photos of Geopora sporocarps

Name Derivation

Named by Harvey Wilson Harkness (1821-1901) (1885), pioneer of truffle taxonomy in America, from Greek, geo- (earth) and -pora (autumn), hence an autumn-fruiting, below-ground fungus.

Distribution

Northern Hemisphere in association with ectomycorrhizal host trees. Geopora cooperi is the most common and widely distributed species; its two forms are mostly associated with members of the Pinaceae. Geopora clausa occurs in xeric regions, often in association with Salicaceae in oases or along rivers.
Season: Throughout the year as weather conditions permit.
Species known from North Temperate Forests: Twelve, G. cooperi and G. clausa only being strictly hypogeous.

Keys and Descriptions

Burdsall (1968).