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truffle(trŭf`əl) [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, or Périgord 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 black truffles found in the forests of Périgord, France, have been highly regarded since the 15th cent., and their collection and cultivation is an important industry. 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. Black truffle cultivation has been somewhat successful since the late 20th cent.; it requires the inoculation of the roots of a seedling of its host plants, oak, hazel, and other deciduous trees, with fungal spores. The prized white truffle, harvested primarily in central and N Italy as well as in parts of S France, Croatia, and Slovenia, is more expensive and has not been successfully cultivated.
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 summer, or burgundy, truffle, T. aestivum, a black truffle widely found in Europe, is most often associated with beech trees and is also prized for culinary use. T. indicum, a black truffle exported from China, where it grows on pine and chestnut roots, is regarded as inferior to the Périgord and summer truffles. The tasty Oregon white truffle, T. oregonense, grows 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.
an ascomycetous. fungus with a fleshy, tuberous subterranean fruiting body. Most truffles belong to the order Tu-berales. They grow in forests as saprophytes or form mycorrhizae with tree roots. Some of the fruiting bodies resemble marble in cross section.
There are a few edible species of truffles. The most valuable is the very aromatic Tuber brumale, which is black and warty on the outside and dark gray or reddish black with light veining on the inside. Tuber brumale grows in oak and beech groves, mainly in southern France and northern Italy, where it has great commercial value. The species Choiromyces meandriformis, whose light-fleshed fruiting body resembles a potato in form and size, grows in the forests of Western Europe, the western USSR, and Moscow Oblast. Truffles of the genus Terfezia, which belong to the order Plectascales, include a number of edible species but are of less value than Tuber brumale. They grow in Southern Europe, North Africa, and Southwest Asia, as well as in the Azerbaijan and Turkmen SSR’s of the USSR.
Inedible basidial fungi of the genus Scleroderma of the order Gastromycetes, whose fruiting bodies are in the form of rounded or elongated yellow tubers 3–10 cm long, are sometimes erroneously called truffles. The fungi are found in forests and parks. Their fruiting bodies have an unpleasant odor and initially are solid, with a black interior and light veining; the interior later disintegrates.