The nuts are edible kernels of the fruits from tree belonging to Juglandaceae family, in the genus:Juglan. Juglan species plants are medium sized, semi-tropical, deciduous trees believed to be originating in the mountain ranges of Central Asian or southern Europe region.
There exist at least 30 varieties of walnut cultivars. The three popular verities grown for the commercial purpose are the English or Persian walnut(Juglans regia), the Black walnut(Juglans nigra), and the White or butternut walnut(Juglans cinerea). Commercially, the nuts are being cultivated in the United States of America, Romania, France, Turkey, and China. After plantation, the tree takes approximately four years until it produces its first major crop