Truffle Genus: Truncocolumella

Truncocolumella citrina basidiospore scale = 10 µm

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

Spore Characters

Surface: Smooth or rarely minutely roughened.
Shape and Size: Symmetrical and cylindrical to fusoid (spindle-shaped), 6-10 x 3.5-5 µm; attachment straight, an inconspicuous nipple or a basal.
Wall: Single, thin except for a few species with walls up to 2 µm thick; apical pore lacking.
Color in Water: Hyaline to pale yellow; spores that are individually hyaline are often yellow in mass.

View photos of Truncocolumella spores

Sporocarp Characters

Shape and Size: Generally similar to Rhizopogon.
Peridium: Yellow and felty.
Gleba: Gray to olive or brown, with empty chambers and a prominent, pale yellow to yellow columella penetrating the gleba from the sporocarp base. In contrast to Rhizopogon, which lacks a columella.
Odor: Fruity to mushroomy.

View photos of Truncocolumella sporocarps

Name Derivation

From Latin, trunc- (trunk) and -columella (little column), named by distinguished Oregon mycologist and plant pathologist, Sanford Zeller (1884-1948) (1922) in reference to the "tree-like column" of sterile tissue (columella) that penetrates the gleba from the base.

Distribution

Truncocolumella citrina is most abundant in association with Pseudotsuga menziesii (Mirb.) Franco in the Pacific Northwest, but occasionally occurs east to the Rocky Mountains.
Season: Summer and early autumn.
Species known from North Temperate Forests: One.

Keys and Descriptions

Smith and Singer (1959).