The owner of a grove of cork oaks must wait ten years between crops of the bark, but every year three crops of acorns are borne on these trees. The pigs of the owner, turned into the grove, fatten on this rich food. So the little trees are very profitable in two ways.
In the south of Europe, the handsome, evergreen holm oak grows wild; its glossy leaves and compact form remind us of our holly trees. It is one of the most valuable ornamental oaks, but as a fruit tree, it has unusual value. Its acorns are sweet and rich, and the crop is heavy. Hogs are fattened upon them. In earlier days they were used as human food, and even now gipsies gather them to eat. Its acorn cups, bark, and the galls it bears are of the very best quality. They are used in the most particular jobs of dyeing and tanning.
Under ground, the holm oak bears a strange fruit—a fungus called “truffle” develops on the roots. These truffles are somewhat like mushrooms in their growth. They are far more delicious to eat, and expensive to buy than ordinary mushrooms. The best of them are found in France, and French people are especially fond of them.
Trees that grow on chalky lands are more likely to produce truffles. At a dozen years old, they begin to yield, and truffles may be found upon their roots for about twenty-five years.
Not every holm oak has truffles on its roots. The finding of these delicacies is a very interesting and exciting game, and a great deal of a lottery. There is but one way to find them, and that is by the sense of smell. The truffle has a rich, strong odour. Dogs and pigs are the only animals that are able to find it. The truffle-hunter is usually an old woman, who goes with a trained pig or a trained dog into the oak forest. She has a basket, and a spading fork, and she keeps a close eye on her four-footed partner. If the pig, in rooting about under an oak, suddenly becomes excited, and begins to root furiously, she drives him away, and digs out the precious ball of fungus he has scented. It is irregular in form, and looks somewhat like a potato. Meanwhile the pig locates another, and is again disappointed. The truffle dog is treated in the same manner. Unless put into a pen, or chained at night, these truffle-hunters are likely to take to the woods and feast when no one is by to interfere with their pleasure.
Truffles are shipped in cans to the United States, but we have not yet discovered them growing on the roots of our oak trees. Probably we have not yet looked for them with sufficient care and patience.
APPENDIX
APPENDIX
IDENTIFICATION KEYS TO TREE GROUPS AND FAMILIES
A KEY TO NEEDLE-LEAVED EVERGREENS
A. Leaves few, in sheathed bundles, set spirally on the twig. THE PINES. AA. Leaves solitary, set spirally on the twig. B. Twigs with bracket-like projections for attachment of leaves; cones hanging down. C. Leaves flat, blunt, with short stalks. The Hemlocks. CC. Leaves angled, sharp, without stalks. The Spruces. BB. Twigs smooth; cones standing erect. The Firs.