The truffle is a hypogeal fungus that forms in the soil at a depth of 10-50 cm, assuming variable dimensions. It gets from the roots of the plants all the nutrients necessary for its development. This fruit is characterized by an external covering (peridium) and an internal pulp (gleba) that, when cut, appears marbled due to the presence of chiaroscuro veins. The dark veins form the fertile areas of the carpophore (fruiting body) and contain the spores, to which the reproductive function is delegated.
The truffle is made up of 95% water, fibres, mineral salts and organic substances provided by the tree with which it lives in symbiosis. The shape depends on the characteristics of the soil in which it develops: the soft one favors the growth of a spherical truffle, while a hard soil usually leads to a lumpy shape.