Truffles, underground fungi, used as food; those of commerce belonging to the genus tuber, while others which bear the name are of related but different genera. The early English writers called them "trubbes," both names being derived through the Italian from the Latin terra tuber. They are somewhat oblong or globose, varying from two ounces to several pounds in weight, according to species and locality; there are white kinds, but generally the surface is blackish or brownish, and roughened with warty protuberances. When cut open they present a variously marbled appearance, and have no resemblance to the generally known forms of fungi; the hy-menium, or reproductive portion, is found in the veins which traverse the mass in all directions; in these are found minute sacs, each containing several spores, the surface of which is covered with spines or is honeycombed. But little is known about their early development, and their mycelium, or vegetative portion; when mature, they are quite free from attachment to any other body.
Truffles are generally found in calcareous soils, and always in woods, of oak or beech; hence it has been inferred that at some stage of their existence they are parasitic upon the roots of trees; they are found in many parts of England, more abundantly on the continent, and in Africa. The existence of truffles in the United States is very doubtful; the occasional announcement of their discovery is due to the finding of the Indian bread. (See Tuckahoe.) In England truffles are hunted by a particular breed of dogs, which are trained by hiding a truffle and teaching them that their food depends upon finding it by the scent; the dogs become so expert that they rarely make a mispoint; when the truffle is dug up, the dog is rewarded with a bit of food. On the continent a similar service is performed by sows. The attempts to cultivate the truffle have not been successful, as the mycelium or spawn, the vegetative portion of the plant, which allows mushrooms to be cultivated so readily, has not yet been obtained. They have been produced by sprinkling the earth with water in which the parings of truffles had been steeped; and in some parts of France a piece of calcareous soil, sown with acorns, has yielded truffles as soon as the saplings attained a few years' growth.
The English truffles are tuber Oestivum; the more highly prized French are T. melanosporum, and the Piedmontese, which bring the highest price of all, T. mognatum; several others are known which are not found in commerce. In Algiers a truffle of another genus (terfezia), and of fair quality, is remarkably abundant, and several have been found in Australia. Truffles have an odor and flavor peculiarly their own, and though sometimes cooked by themselves, they are most generally used for communicating their flavor to meats. The truffles used in this country are imported in sealed tin cans. - The production of truffles in France in 1874 amounted to 1,588,100 kilogrammes (one fourth in the department of Vau-cluse), valued at 15,588,100 francs.
French Truffle (Tuber melanosporum).