English name: Black Walnut
black walnut, (Juglans nigra), also called eastern black walnut, tall tree of the walnut family (Juglandaceae), native to eastern North America and valued for its decorative wood. The dark fine-grained wood of black walnuts is used for furniture, paneling, and gunstocks. The trees are also planted as ornamentals and are cultivated for a dye found in the fruit husks. The edible seed is of limited commercial importance. See also walnut.
A black walnut tree usually is between 20 and 30 metres (about 65 and 100 feet) tall and has a trunk about 60 to 90 cm (2 to 3 feet) in diameter, with deeply furrowed dark brown or grayish black bark. The leaves, about 30 to 60 cm (1 to 2 feet) long, consist of 15 to 23 leaflets borne on very short stalks. The fruit is a drupe. The pit of the drupe, commonly called the nut, contains a sweet oily seed; the outer drupe is a yellow-green hairy husk. The roots of the tree exude chemicals called juglones that can inhibit the growth of others plants, including a number of common ornamental and food plants such as azaleas, blueberries, tomatoes, and peppers. Black walnut grows slowly, maturing on good soils in about 150 years; it may have a life span of more than 250 years.