Truffle

Truffle, any of a group of edible, spherical fungi that grow underground. The truffle was known to ancient Babylonians, Greeks, and Romans.

A truffle reaches about 2.5 to 10 cm (about 1 to 4 in) in diameter, varies in color from white or gray to dark brown, and has a knobby exterior surrounding a fleshy interior. The truffle usually grows in forests on or close to tree roots. Because it can grow 8 to 30 cm (3 to 12 in) below the soil surface, truffle collectors traditionally use dogs or pigs trained to locate the fungus by scent.

A fresh truffle has a delicate taste and aroma, and like a mushroom, is low in nutritional value. The largest and best truffles grow in northern Italy and southern France where they support an important industry. The truffle also grows in other regions of Europe, the British Isles, and North America, where it was introduced from Europe. One of the best-known and most highly valued species is the black Périgord truffle, named after the region in France where it grows. It is brown-black and covered with many warts. The unique-tasting, black flesh of the Périgord is frequently canned after harvesting. The white, or Piedmont, truffle, native to Italy, is ocher with gray-white flesh. It has a pungent, earthy scent and usually is sliced or grated raw and served in salads, egg dishes, or pasta. The rare summer truffle is found in beech forests. It is brown-black with white flesh that turns yellow when cut.

Scientific classification: Truffles belong to the family, Tuberaceae, in the order, Tuberales, of the class Ascomycetes. The Périgord truffle is classified as Tubermelanosporum; the white, or Piedmont, truffle as Tuber magnatum; and the summer truffle as Tuber aestivum.