Truffle Genus: Sclerogaster

Sclerogaster nevophilum basidiospore

Kingdom: Fungi Phylum: Basidiomycota Order: Geastrales Family: Uncertain

Spore Characters

Surface: Nearly smooth to ornamented with spines, warts, or cones up to 2 µm tall.
Shape and Size: Globose, 4-10 µm in diameter (excluding ornamentation); sterigmal attachment straight, prominent to inconspicuous.
Wall: Thick, single, 0.5-1 µm in diameter.
Color in Water: Hyaline to yellow or pale brown.
Melzer's Reaction: Not distinctive.
Comments: The largest Sclerogaster spores barely overlap the smallest Octaviania spores. The small-spored Sclerogaster species will not separate readily from Radiigera species in the key.

View photos of Sclerogaster spores

Sporocarp Characters

Shape and Size: Globose to irregular, 3-20 mm in diameter, often in close clusters in humus or soil.
Peridium: White to pale yellow-brown, sometimes staining rose where bruised; surface smooth to floccose and bound to surrounding organic matter, often easily separable from the gleba.
Gleba: Pale yellow to deep yellow, orange, yellow-brown or brown, with small chambers filled with spores embedded in gel at maturity. The tramal plates are narrow and paler than the spore mass; columella absent to moderately developed.
Odor: Not distinctive or of vitamin B.

View photos of Sclerogaster sporocarps

Name Derivation

Named by German mycologist Rudolph Hesse (1844-1912) (1891) from Greek, sclero- (hard) and -gaster (literally "stomach" but in mycology generally referring to Gasteromycetes, i.e. puffballs) hence, "hard puffball" in reference to the very firm consistency of some species.

Distribution

Western North America and western Europe.
Season: Late spring through autumn.
Species known from North Temperate Forests: Ten, with at least one more undescribed.

Keys and Descriptions

The monograph by Dodge and Zeller (1936) has been supplemented with a description of a new species by Fogel (1977b). Montecchi and Sarasini (2000) cover European taxa.