What is "juglans nigra"

Walnut \Wal"nut\, n. [OE. walnot, AS. wealh-hnutu a Welsh or foreign nut, a walnut; wealh foreign, strange, n., a Welshman, Celt (akin to OHG. Walh, properly, a Celt, from the name of a Celtic tribe, in L. Volcae) + hnutu a nut; akin to D. walnoot, G. walnuss, Icel. valhnot, Sw. valn["o]t, Dan valn["o]d. See Nut, and cf. Welsh.] (Bot.) The fruit or nut of any tree of the genus Juglans; also, the tree, and its timber. The seven or eight known species are all natives of the north temperate zone.

Note: In some parts of America, especially in New England, the name walnut is given to several species of hickory ( Carya), and their fruit.

Ash-leaved walnut, a tree ( Juglans fraxinifolia), native in Transcaucasia.

Black walnut, a North American tree ( Juglans nigra) valuable for its purplish brown wood, which is extensively used in cabinetwork and for gunstocks. The nuts are thick-shelled, and nearly globular.

English walnut, or European walnut, a tree ( Juglans regia), native of Asia from the Caucasus to Japan, valuable for its timber and for its excellent nuts, which are also called Madeira nuts.

Walnut brown, a deep warm brown color, like that of the heartwood of the black walnut.

Walnut oil, oil extracted from walnut meats. It is used in cooking, making soap, etc.

White walnut, a North American tree ( Juglans cinerea), bearing long, oval, thick-shelled, oily nuts, commonly called butternuts. See Butternut.

Juglans nigra, the eastern black walnut, is a species of deciduous tree in the walnut family, Juglandaceae, native to eastern North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida and southwest to central Texas. Wild trees in the upper Ottawa Valley may be an isolated native population or may have derived from planted trees.

Black walnut is an important tree commercially, as the wood is a deep brown color and easily worked. The fruits, walnuts, are cultivated for their distinctive and desirable taste. Often, trees are grown for both lumber and walnuts simultaneously and many cultivars have been developed for improved quality nuts or wood. Black walnut is currently under pressure from the thousand cankers disease which is causing decline of walnuts in some areas. Black walnut is also allelopathic which means that it releases chemicals from roots and other tissues which harm other organisms and give the tree a competitive advantage, this is often undesirable as it can harm garden plants and grasses.