19. Tuber cibarium, Sibth.—Common Truffle.
Lycoperdon Tuber, Linn.; Tubera, Tourn.; Tubera sincera, Pliny, lib. xix. cap. 11. Dr. Sibthorp (Florae Gr. Prodr. ii. 352) considers it to be the ύδνον of Diosc. lib. ii. cap. 175: its modern Greek name being ύδνοσ ή ίκνος: but Fries, while he admits, on the authority of Sprengel, that it is the ύδνον of Theophrastus (Hist. Pl. lib. i. cap. 9), says it is certainly not the ύδνον of Dioscorides [Systema Mycologicum, vol. ii. p. 290, 1822.].
The truffle of the markets occurs in rough, rounded nodules, varying in size from a filbert to the fist, cracked into small subpyramidal warts. Internally, it is marbled or veined. The white portions are filamentous, and are regarded by the Rev. M. J. Berkeley as constituting a sort of mycelium to the darker portions, which he calls the veins: the latter are cellular, and contain many subovate, shortly pedicellated sporangia, at first filled with a granular mass, which is ultimately collected into one or two globular, yellowish echinulate sporidia.
In France, three varieties of truffle are known [Mérat and De Lens, Dict. Univ. de Mat. Méd. t. vi. 783.]: the truffle de Perigord with black flesh; the truffle de Bourgogne with white flesh; and a third sort with violet flesh. The first is the most esteemed, on account of its odour and tenderness.
This fungus grows several inches below the surface of the ground in several parts of England. Covent garden market is chiefly supplied from the downs of Wiltshire, Hampshire and Kent. Its odour is peculiar and penetrating, by which its presence is detected. In this country it is usually hunted by dogs trained for the purpose: in Italy, by pigs.
Riègel [Pharmaceutisches Central-Blatt für 1844, p. 17; also, Chem. Gaz. vol. ii. p. 137.] analyzed the dried Perigord truffles, and found them to consist of a brown fat oil (olein) with traces of volatile oil, an acrid resin, osmazome, mushroom sugar, nitrogenous matter insoluble in alcohol, fungic acid, boletic acid, phosphoric acid, potash, ammonia, vegetable mucus, vegetable albumen, pectine, and fungine (fungic skeleton).
Truffles are a highly esteemed luxury at the table, being used as a seasoning or flavoring ingredient for ragouts, sauces, stuffings, &c. They are considered to possess aphrodisiac properties; and an Italian physician essayed to prove that births were more numerous in those years which correspond to the more abundant production truffles!