The Common Walnut, is a large and handsome tree, with strong, spreading boughs. Its native place is probably Persia. Other varieties of Walnut, the Black Walnut, the various kinds of Hickory, etc., are mostly natives of North America.
According to Dr. Royle Juglans regia extends from Greece and Asia Minor, over Lebanon and Persia, probably all along the Hindu-Kush to the Himalayas. It is abundant in Kashmir, and is found in Sirmore, Kumdon and Nepal. The walnuts imported into the plains of India are chiefly from Kashmir. Dr. Hooker states that in the Sikkim Himalaya, the Walnut inhabits the mountain slopes at an elevation of 4,000 to 7,000 feet. According to Pliny, it was introduced into Italy from Persia, and it is mentioned by Varro, who was born B.C. 116, as growing in Italy during his lifetime.
The tree grows to a height of 40 or 60 feet, with a large spreading top, and thick, massive stem. The flowers of separate sexes are borne upon the same tree and appear in early spring before the leaves. The male flowers have a calyx of five or six scales, surrounding from eighteen to thirty-six stamens; whilst the calyx of the female flowers closely envelops the ovary, which bears two or three fleshy stigmas. The deciduous leaves are pinnate.