Truffle Genus: Sphaerosoma

Sphaerosoma fuscescens ascospore scale = 10 µm

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

Spore Characters

Surface: Smooth to reticulate, the ornamentation 2-3 µm tall.
Shape and Size: Globose, 17-20 µm in diameter excluding ornamentation.
Wall: Single, thin.
Color in Water: Hyaline.
Melzer's Reaction: Deep orange to dextrinoid.
Comments: Sphaerosoma is the only genus with hyaline, reticulate spores that are strongly orange to dextrinoid in Melzer's reagent.

View photos of Sphaerosoma spores

Sporocarp Characters

Shape and Size: Subglobose, 5-15 mm in diameter.
Peridium: Lacking, the outer surface of the sporocarp white to brown, uniform hymenium.
Gleba: Lacking, the basal tissue instead supports the outer hymenial surface.
Odor: Not known.

Name Derivation

Coined by German botanist Johann Fridrich Klotzsch (1805-1860) and Albert Gottfried Dietrich (1795-1856) (1839) from Greek, sphaero- (sphere) and -soma (body), hence "spherical body."

Distribution

Australia and Europe, introduced from Australia on roots of Eucalyptus species or other members of the Myrtaceae.
Season: Autumn.
Species known from North Temperate Eucalyptus Plantations: One, S. fuscescens Klotzsch and Dietrich.

Keys and Descriptions

Dissing and Korf (1980) describe S. fuscescens and the taxonomic confusion that surrounded it in the past.