Walnut (Juglans species)

Walnut treeWalnuts grow on very large trees, often reaching 18 meters (54 feet) tall, with some growing as high as 40 meters (130 feet) tall. Walnut trees often have divided (split or forked) trunks with wide-spread crowns of foliage at the top of the tree.  Walnut trees have divided leaves, with feather patterned veins, which grow alternately on the branch, 9-15 leaflets per leaf, each leaf about 7-13 inches long. The leaves are narrow, oval to lance shaped, and somewhat curved, yellowish green on top and paler green underneath.  On males, the flowers are yellowish green catkins (2-3 inches long) hanging from the prior year’s twigs.  On female Walnut trees, the flowers occur on spikes either singly or in clusters of 2-3 flowers near the ends of the current year’s twigs.  The twigs of the Walnut are hollowish with empty chambers on the inside.

Diagram of Walnut tree components including branch, leaves, nuts, and flowersThe walnut itself is single-seeded, about 1-2 inches in diameter with a grooved, thick outer husk that must be removed to reach the hard, wrinkly, inner shell of the nut (which is in two halves).  The husks are initially green and leathery but turn brown when mature.  The bark of the Walnut tree is grayish brown with flat topped ridges.

Where to Find: The English walnut, in the wild state, is found from southeastern Europe across Asia to China and is abundant in the Himalayas. Several other species of walnut are found in China and Japan. The black walnut is common in the eastern United States.

Edible Parts: A husked walnutThe nut kernel ripens and the husk hardens in the autumn. You extract the walnut meat by cracking the shell. Walnut meats are highly nutritious because of their protein and oil content and are rich in fiber, B vitamins, magnesium, and antioxidants.

Other Uses: You can boil walnuts and use the juice as an antifungal agent. The husks of “green” walnuts produce a dark brown dye that can be used for clothing or camouflage. Crush the husks of “green” black walnuts and sprinkle them into sluggish water or ponds for use as fish poison.

Walnut tree bark is grayish, rough, and ridged

Walnut tree trunks often fork or split

Walnut tree fruit husk and seed (nut)

When immature (unripened), walnuts are green with leathery husks

Walnut tree leaves

Walnut tree leaf pattern

Walnut tree nut and leaflets

Walnut tree leaflets

Color diagram of Walnut tree illustrating leaves, flowers, husks, and nut

Color diagram of Walnut tree illustrating leaves, flowers, husks, and cross sections of nut

Color diagram of Walnut tree illustrating leaves, flowers, husks, and nut