Truffle Genus: Scleroderma

Scleroderma hypogaeum basidiospores scale = 10 µm

Kingdom: Fungi Phylum: Basidiomycota Order: Boletales Family: Sclerodermataceae

Spore Characters

Surface: Reticulate to spiny or with cones.
Shape and Size: Globose, 15-30 µm in diameter including ornamentation.
Wall:
Color in Water:
Melzer's Reaction:
Comments: These spores are difficult to separate from those of Elaphomyces, because the spore attachment is not usually evident with S. hypogaeum.

View photos of Scleroderma spores

Sporocarp Characters

Shape and Size: Subglobose to irregular, with a cluster of rhizomorphs at the base, 2 - 6 cm in diameter.
Peridium: Pale brown or pale yellow to brown-yellow, in youth with a rosy blush where bruised, and pink where cut, smooth to slightly scaly, 0.5-6 mm thick.
Gleba: White and solid in youth, at maturity an olivaceous black to purple-black powdery spore mass.
Odor: Not distinctive to farinaceous, fishy or rancid.

View photos of Scleroderma sporocarps

Name Derivation

Named by Christian Hendrik Persoon (1761-1836) (1821) from Greek, sclero- (hard) and -derma (skin), "hard skin" or "tough skin" in reference to the thick, crisp to leathery peridium characteristic of the genus.

Distribution

The genus is worldwide, but truffle-like species occur only in ectomycorrhizal forests of western North America and Australia.
Season: Summer through autumn.
Species known from North Temperate Forests: About 20, but only one, Scleroderma hypogaeum Zeller, is hypogeous; the others are not likely to be involved in mammal mycophagy. At least 11 hypogeous species occur in Australia.

Keys and Descriptions

Guzmán (1970) monographed the genus Scleroderma on a worldwide basis. Scleroderma hypogaeum is described in detail by Zeller (1922) and again later as S. arenicola (Zeller, 1947).