Tuber oregonense, commonly known as the Oregon white truffle, is a species of edible truffle in the genus Tuber. Described as new to science in 2010, the North American species is found on the western coast of the United States, from northern California to southern British Columbia west of the Cascade Range. A mycorrhizal fungus, it grows a symbiotic association with Douglas fir. It overlaps in distribution with the closely related T. gibbosum, but they have different growing seasons: T. oregonense typically appears from October through March, while T. gibbosum grows from January to June. The fruit bodies of the fungus are roughly spherical to irregular in shape, and resemble small potatoes up to 5 cm (2.0 in) in diameter. Inside the truffle is the gleba, which is initially white before it becomes a marbled tan color. The large, often thick-walled, and strongly ornamented spores are produced in large spherical asci. The truffle is highly prized for its taste and aroma. Attempts to cultivate the truffles in Christmas tree farms have been successful.