The order Tuberales contains the truffles, which are subterranean fungi, ranging in size from an acorn to a good-sized potato. The asci or spore-sacs are formed on the interior of the fungus, the warty truffle itself being called an ascoma, as it contains the asci.
Since the time of Pliny and Dioscorides, truffles have been known and esteemed as a table delicacy. Since they mature underground, they must be hunted for by dogs and pigs trained for the purpose. A pig will scent a truffle at a distance of twenty feet, and will run quickly to the spot to dig it out with her snout. An attendant must follow the pig to secure the truffle before the pig eats it. Edible species have not been found growing in this country.