truffle

truffle [Fr.], subterranean edible fungus that forms a mutually beneficial (symbiotic) relationship with the roots of certain trees and plants. The part of the fungus used as food is the ascoma, the fruiting body of the fungus. The best-known truffles are the black, Tuber melanosporum, and the white, T. magnatum, both found chiefly in W Europe. Their flavor is piquant and aromatic, and they have been esteemed as a delicacy from ancient times; recipes for their use are found in Greek and Roman writings. The truffles found in the forests of Périgord, France, have been highly regarded since the 15th cent., and their collection is an important industry. Some are canned for export. Traditionally hunted with pigs, they are now mainly found by dogs, which can be trained to "point" for truffles and have the distinct advantage of not being truffle eaters. Truffle cultivation has had some success; it requires the inoculation of the roots of a host plant seedling with fungal spores. T. indicum, a black truffle exported from China, is regarded as inferior to T. melanosporum.

Besides the well-known white and black truffles, there are hundreds of other species, all mycorrhizae, fungi in a symbiotic relationship with plant roots. The tasty Oregon white truffle, T. gibbosum, for example, grows only on the roots of the Douglas fir tree, which is dependent upon the fungus for its mineral nutrition. Truffles are widespread in distribution and are found in a wide variety of habitats.

truffle The underground fruit body of certain species Tuber. Truffles are edible and highly esteemed. T. aestivum (summer truffle) is 2–8 cm in diameter and has a dark brown, warty surface. The inside is greyish with a network of white veins. It is occasionally found in England in the soil of beech woods. T. melanosporum (the black or Périgord truffle) occurs in S. Europe and resembles T. aestivum but is rather smaller (1–3 cm).