Truffle Genus: Fischerula

Fischerula subcaulis ascospore scale = 10 µm

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

Spore Characters

Surface: Smooth in youth, soon developing conic warts, broad ridges, or agglutinated, flexuous spines.
Shape and Size: Ellipsoid, 40-77 (-101) x 25-29 µm excluding ornamentation.
Wall: Single, 1-2 µm thick.
Color in Water: Hyaline in youth, becoming dark brown at maturity.
Melzer's Reaction: Dark red-brown.
Comments: Only Fischerula species combine a warty, ridged, or agglutinated-spiny spore ornamentation with large spore size (i.e., spores commonly longer than 50 µm).

View photos of Fischerula spores

Sporocarp Characters

Shape and Size: Subglobose to turbinate to irregular, with a basal tuft of hyphae, often with a short stem, 0.8-2.5 cm in diameter.
Peridium: Yellow-pink to brown or dark brown, scabrous.
Gleba: Solid, at maturity brown marbled with white to gray-yellow veins that more or less radiate outward from the base or the columella to emerge through the peridium; columella when present gray-red-brown.
Odor: Not distinctive.

View photos of Fischerula sporocarps

Name Derivation

Named by Italian mycologist Oreste Mattirolo (1856-1947) (1928) in honor of the early 20th-century Swiss mycologist, Eduard Fischer, who devoted much study to the truffles.

Distribution

Fischerula subcaulis occurs on the coast and in the coastal mountains of Oregon and Washington in association with Pseudotsuga menziesii. F. macrospora has been found only in central and southern Italy.
Season: Late spring through late autumn.
Species known from North Temperate Forests: Two (the only two known for the genus).

Keys and Descriptions

Trappe (1975b).