sisal hemp [from Sisal, former chief port of Yucatan], important cordage fiber obtained from the leaves of the sisal hemp plant, an extensively cultivated tropical agave (family Agavaceae or Liliaceae). It is considered second to Manila hemp in strength and value and is used chiefly for cordage. About half the sisal produced is exported to the United States and Canada, where much of it is used as binding twine for grain-harvesting machines. True sisal (Agave sisalana), henequen (Agave fourcroydes), and many other similar fibers from the agave and closely related genera are often collectively called sisal hemp. Henequen [from the Mexican name; its fiber was used by the pre-Columbian Native Americans] is grown chiefly in Yucatan, and production of henequen twine is a major industry there. The false sisal of Florida (A. decipiens) produces an inferior fiber. Sisal hemp is classified in the division Magnoliophyta, class Lilopsida, order Liliales.

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 chiefly in the Midwest. 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 is used medicinally and is 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. 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.

Tampico hemp, fiber of various tropical American plants, among them the agave (see amaryllis).

Manila hemp, the most important of the cordage fibers. It is obtained chiefly from the Manila hemp plant (Musa textilis) of the family Musaceae (banana family). It is grown mainly in its native Philippine Islands, where it has been cultivated since the 16th cent. and is known as abacá. The abacá is in no way related to the true hemp; it is of the same genus as the common banana, which it closely resembles except for the inedible fruit. At maturity the plants are cut down, and the long fibers are taken from overlapping leaves that converge at the base to form a false stem. The fibers are exceptionally strong and durable. The coarser ones are used for binder twine, matting, and rope, particularly marine cordage because of their resistance to the action of saltwater; the finer grades are woven into beautiful native fabrics and hemp hats. Manila paper is made chiefly from old Manila hemp ropes and is valuable as a strong wrapping paper. Manila hemp is classified in the division Magnoliophyta, class Liliopsida, order Zingiberales, family Musaceae.

Stout, aromatic, erect annual herbaceous plant (Cannabis sativa, family Cannabaceae), the sole species of cannabis; also, its fibre. Hemp originated in Central Asia and is now cultivated widely in the northern temperate zone. A tall, canelike variety is raised for the fibre; a short, more branched variety is prized as the more abundant source of marijuana. Hemp fibre is strong and durable and is used for cordage and for artificial sponges and such coarse fabrics as sacking (burlap) and canvas. Hemp is grown primarily for fibre in most countries.

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