Truffle

a genus of subterranean fungi, much esteemed as a table delicacy. There are about fifty species. They have the shape of a potato and are black or bluish outside with a white interior. They range in size from that of a Brazil nut to that of a large potato. They grow limy soil, usually in birch or oak forests. They never appear above ground. In France hogs are trained to root them out. In England dogs are trained to locate them and indicate their presence by scratching. In both cases the finder is rewarded, the sow by an acorn, the dog by some other dainty. The truffles of France are the most celebrated. See Fungus; Mushroom