Originally from North America but imported in Europe since the last century, the American Walnut is also known as Canaletto Walnut, with reference to the canals that spread chlorophyll in the trunk of the tree. Although walnuts are difficult to open, it was a food source for Native Americans, who also made flutes and tribal objects with its wood. It is an allelopathic plant, that is, it has the characteristic of releasing substances that prevent the growth of other plants around its roots.