Truffle Genus: Rhopalogaster

Rhopalogaster transversarium basidiospores

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

Spore Characters

Surface: Smooth.
Shape and Size: Longitudinally symmetric, ellipsoid, 5.8-7.2 x 3.5-4.3 µm.
Wall: Single, thin.
Color in H2O: Yellow-brown.
Melzer's Reaction: Not distinctive.
Comments: Similar to spores of some Rhizopogon and other look-a-likes but the spores of Rhopalogaster are distinctly yellow-brown.

View photos of Rhopalogaster spores

Sporocarp Characters

Shape and Size: Club-shaped, 3-7 cm tall, 1.5-2.5 cm broad.
Peridium: Brown to yellow-brown, smooth to scaly.
Gleba: Chambered with spores lining the chambers, yellow-brown to olive brown.
Stem: Distinct stem that extends through the gleba as a percurrent columella.
Odor: Not distinctive.

View photos of Rhopalogaster sporocarps

Name Derivation

Named by John R. Johnston (1903) from Latin, Rhopal- (club-like) and gaster- (literally "stomach" but in mycology referring generally to Gasteromycetes, i.e. puffballs), hence, "a club-like puffball."

Distribution

Southern United States in coniferous forests on organic matter.
Season: Autumn.
Species known from North Temperate Forests: One, Rhopalogaster transversarium, the only species of the genus.

Keys and Descriptions

Miller and Miller (1988).