Pine nuts are the edible seeds of some species of pine trees. About 20 species of the genus produce seeds large enough to justify their cultivation. In other species pine nuts are too small to be appreciated as food, even if edible. In Europe there are two species of pine that produce large seeds. The best is the domestic pine (Pinus pinea) which is also not by chance called "pine nuts". Swiss pine (Pinus cembra) produces large seeds, but lives in more difficult areas. Pine nuts are rich in protein and have been consumed in Europe since the Paleolithic period. They are also a source of dietary fiber. Pine nuts are essential for pesto and a variety of other dishes including cakes. Freshly extracted from the strobe, the pine nuts are covered with a rigid casing. The seed is fed by the female tissue (gametophyte) that supportssporophyte, or seed. Despite some similarities, pine nuts are not nuts, since, being produced by gymnospermes, they do not have the outer carcarpello. Pine nuts are called piñones in Spanish and pine nuts in English. In various areas of Italy they are called by other names such as "pinoccoli" or "pinocchi", hence the name of the famous puppet Pinocchio. Other species of pine are grown for seeds in other parts of the world. In Asia in particular, Pinus koraiensis and Pinus gerardiana are cultivated Four other species Pinus sibirica, Pinus pumila, Pinus armandii and Pinus bungeana are less used. In North America the three most widely used species are Pinus edulis, Pinus monophylla and Pinus cembroides. Other species such as Pinus orizabensis, Pinus johannis, Pinus culminicola, Pinus remote, Pinus quadrifolia, Pinus sabineana, Pinus torreyana and Pinus lambertiana are less widely used. Pine nut-like seeds are also produced from species of the genus Araucaria.