hemp

hemp

hemp, common name for a tall annual herb (Cannabis sativa) of the family Cannabinaceae, native to Asia but now widespread because of its formerly large-scale cultivation for the bast fiber (also called hemp) and for the drugs it yields. Known and cultivated in ancient China, the plant was introduced into Europe before the Christian era. In the United States it was cultivated for fiber chiefly in the Midwest, but competition from synthetic materials led to reduced crops, and antidrug legislation led to a federal ban (1970) on hemp growing without a permit. Federal legislation in 2014 eased restrictions on the growing of industrial hemp (which has very little drug content) for research purposes, and additional legislation in 2018 permitted the regulated commercial growing of industrial hemp. The fiber, retted from the stem, was one of the most important for various kinds of cordage; it was also used in making paper, cloth (canvas and other kinds), oakum for calking ships, and other products. The male and female flowers are borne on separate plants. The chemical derived from the female flowering tops in strains bred for their drug content is used medicinally; the tops are also the source of marijuana and hashish. Hemp seed is used as bird food, and the oil from the seeds is used in the manufacture of paints, varnishes, and soap and in cooking. The dried leaves are used in Asia for a beverage. The word hemp is used in combination for several other kinds of fiber plants, notably Manila hemp and sisal hemp. The true hemp plant is related to the hop, which is used in making beer. Hemp is classified in the division Magnoliophyta, class Magnoliopsida, order Urticales, family Cannabinaceae.

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Hemp

One of the oldest cultivated crops, its use dates back to the stone age. Hemp is one of the most environmentally friendly fibers in the world and requires no pesticides, herbicides, or fertilizers, and it uses very little water. Hemp exhibits eight times the strength of cotton and can be woven into a variety of textures. Although currently illegal to cultivate in the United States, hemp is a fast-growing, environmentally sound substitute for cotton and wood fibers that requires little or no chemicals to produce paper, textiles, and a variety of other products.

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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Hemp

 

the coarse bast fiber from the stem of hemp plants (Cannabis sativa). The bast fibers from other plant species are also called hemp, for example, Manila hemp. Industrial hemp consists of elementary fibers measuring 14–15 mm long that are glued together. Fibers more than 700 mm long are obtained by breaking and scutching the washed and dried stems of C. sativa. Short fibers measuring 175–250 mm long are obtained from cleaning the by-products of scutching; they are also obtained from the short, matted, entangled, low-quality straw. Hemp is used to manufacture rope, string, twine, fishnets, canvas, sailcloth, and materials for furniture upholstery and drapery.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

hemp

1. an annual strong-smelling Asian plant, Cannabis sativa, having tough fibres, deeply lobed leaves, and small greenish flowers: family Cannabidaeceae

2. the fibre of this plant, used to make canvas, rope, etc.

3. any of several narcotic drugs obtained from some varieties of this plant, esp from Indian hemp

Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005