User:Sasata/Tuber gibbosum

Tuber gibbosum, commonly known as the Oregon white truffle, is a species of underground mycorrhizal fungi in the family Tuberaceae.

Description
Fruiting body up to 5.5 cm in diameter; roughly spherical and often with lobes. Surface with matted or parallel hairlike cells. The gleba is yellowish when young, becoming reddish-brown at maturity; marbled with white veins often with open spaces. Spores are yellowish brown; ellipsoid, ornamented; 35-52 x 17-39 um.

There are three varieties of T. gibbosum: var. gibbosum, var. autumnnale and var. oregonense. Tuber gibbosum var. gibbosum as originally described by H. W. Harkness occurs from near San Francisco, California, to Victoria, British Columbia in winter and spring. It is characterized by a cinnamon to yellowish brown peridium, a dense, yellowish brown gleba, and ellipsoid to subglobose spores. A second variety, to be described elsewhere as T. gibbosum var. autumnale, fruits from northern California to southwestern Washington in autumn and early winter. It is white in youth, then develops areas of orange to brown and finally becomes dark orange-brown overall; the gleba is not as dense as the type variety, and the spores are ellipsoid to subfusoid. Both varieties have a peridium composed of interwoven hyphae. The third variety, to be described elsewhere as T. gibbosum var. oregonense, is known from only a few autumn collections in western Oregon. It resembles var. autumnale except it has an outer peridial layer of rounded, inflated cells rather than of interwoven hyphae. All three varieties produce emergent hyphal tips with distinctive, irregularly swollen walls.

Habitat and distribution
T. gibbosum forms mycorrhizzal associations with Douglas fir ([[Pseudotsuga menziesii).

This species has been collected along the Pacific Coast in the San Francisco Bay area and northern California, Oregon, and Southern British Columbia, roughly corresponding with the range and distribution of its host tree.