Where do pine nuts, often used to make pesto, come from?

Pine nuts come from pine cones.

More precisely, pine nuts are edible seeds that develop inside the female cones of certain pine species. As the cone matures, its scales protect the seeds, which can later be harvested, removed from their shells, and sold as pine nuts. The familiar culinary ingredient is therefore a seed, not a true botanical nut.

Many pine species produce seeds, but only some have nuts large and flavorful enough for commercial food use. The stone pine, Pinus pinea, is particularly associated with Mediterranean cuisine, while other edible varieties are harvested in Asia and North America. The exact size, flavor, and shell hardness vary by species.

Pine nuts are central to traditional pesto alla Genovese, where they are blended with basil, garlic, hard cheese, and olive oil. They also appear in salads, pastries, stuffings, and sauces. A common misunderstanding is that all pine cones contain commercially useful nuts; in reality, many species produce tiny, hard, or otherwise unsuitable seeds.