What is "juglans regia"

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.

Madeira \Ma*dei"ra\, n. [Pg., the Island Madeira, properly, wood, fr. L. materia stuff, wood. The island was so called because well wooded. See Matter.] A rich wine made on the Island of Madeira.

A cup of Madeira, and a cold capon's leg.
--Shak.

Madeira nut (Bot.), the European walnut; the nut of the Juglans regia.

Juglone \Ju"glone\, n. [L. juglans the walnut + -one.] (Chem.) A yellow crystalline substance ( C10H6O3) resembling quinone, extracted from green shucks of the walnut ( Juglans regia); -- called also nucin. Chemically, it is 5-hydroxy-1,4-naphthalenedione.

Juglandine \Jug"lan*dine\, n. An alkaloid found in the leaves of the walnut ( Juglans regia).

Juglandin \Jug"lan*din\, n. [L. juglans, -andis, a walnut: cf. F. juglandine.] (Chem.) An extractive matter contained in the juice of the green shucks of the walnut ( Juglans regia). It is used medicinally as an alterative, and also as a black hair dye.

Juglans regia, Persian walnut, English walnut, or especially in Great Britain, common walnut, is an Old World walnut tree species native to the region stretching from the Balkans eastward to the Himalayas and southwest China. The largest forests are in Kyrgyzstan, where trees occur in extensive, nearly pure walnut forests at 1,000–2,000 m altitude—notably at Arslanbob in Jalal-Abad Province. It is widely cultivated across Europe.