Hemp: A New Crop with New Uses for North America*

“Hemp” refers primarily to Cannabis sativa L. (Cannabaceae), although the term has been applied to dozens of species representing at least 22 genera, often prominent fiber crops. For examples, Manila hemp (abaca) is Musa textilis Née, sisal hemp is Agave sisalina Perrine, and sunn hemp is Crotolaria juncea L. Especially confusing is the phrase “Indian hemp,” which has been used both for narcotic Asian land races of C. sativa (so-called C. indica Lamarck of India) and Apocynum cannabinum L., which was used by North American Indians as a fiber plant. Cannabis sativa is a multi-purpose plant that has been domesticated for bast (phloem) fiber in the stem, a multi-purpose fixed oil in the “seeds” (achenes), and an intoxicating resin secreted by epidermal glands. The common names hemp and marijuana (much less frequently spelled marihuana) have been applied loosely to all three forms, although historically hemp has been used primarily for the fiber cultigen and its fiber preparations, and marijuana for the drug cultigen and its drug preparations. The current hemp industry is making great efforts to point out that “hemp is not marijuana.” Italicized, Cannabis refers to the biological name of the plant (only one species of this genus is commonly recognized, C. sativa L.). Non-italicized, “cannabis” is a generic abstraction, widely used as a noun and adjective, and commonly (often loosely) used both for cannabis plants and/or any or all of the intoxicant preparations made from them. Probably indigenous to temperate Asia, C. sativa is the most widely cited example of a “camp follower.” It was pre-adapted to thrive in the manured soils around man’s early settlements, which quickly led to its domestication (Schultes 1970). Hemp was harvested by the Chinese 8500 years ago (Schultes and Hofmann 1980). For most of its history, C. sativa was most valued as a fiber source, considerably less so as an intoxicant, and only to a limited extent as an oilseed crop. Hemp is one of the oldest sources of textile fiber, with extant remains of hempen cloth trailing back 6 millennia. Hemp grown for fiber was introduced to western Asia and Egypt, and subsequently to Europe somewhere between 1000 and 2000 BCE. Cultivation in Europe became widespread after 500 CE. The crop was first brought to South America in 1545, in Chile, and to North America in Port Royal, Acadia in 1606. The hemp industry flourished in Kentucky, Missouri, and Illinois between 1840 and 1860 because of the strong demand for sailcloth and cordage (Ehrensing 1998). From the end of the Civil War until 1912, virtually all hemp in the US was produced in Kentucky. During World War I, some hemp cultivation occurred in several states, including Kentucky, Wisconsin, California, North Dakota, South Dakota, Minnesota, Indiana, Illinois, Ohio, Michigan, Kansas, and Iowa (Ehrensing 1998). The second world war led to a brief revival of hemp cultivation in the Midwest, as well as in Canada, because the war cut off supplies of fiber (substantial renewed cultivation also occurred in Germany for the same reason). Until the beginning of the 19 century, hemp was the leading cordage fiber. Until the middle of the 19 century, hemp rivaled flax as the chief textile fiber of vegetable origin, and indeed was described as “the king of fiber-bearing plants,—the standard by which all other fibers are measured” (Boyce 1900). Nevertheless, the Marihuana Tax Act applied in 1938 essentially ended hemp production in the United States, although a small hemp fiber industry continued in Wisconsin until 1958. Similarly in 1938 the cultivation of Cannabis became illegal in Canada under the Opium and Narcotics Act. Hemp, grown under license mostly in Canada, is the most publicized “new” crop in North America. Until very recently the prohibition against drug forms of the plant prevented consideration of cultivation of fiber and oilseed cultivars in Canada. However, in the last 10 years three key developments occurred: (1) much-publicized recent advances in the legal cultivation of hemp in western Europe, especially for new valueadded products; (2) enterprising farmers and farm groups became convinced of the agricultural potential of hemp in Canada, and obtained permits to conduct experimental cultivation; and (3) lobby groups convinced the government of Canada that narcotic forms of the hemp plant are distinct and distinguishable from fiber and oilseed forms. In March 1998, new regulations (under the Controlled Drugs and Substances Act) were provided to allow the commercial development of a hemp industry in Canada, and since then more than a thousand licenses have been issued. Hectares licensed for cultivation for 1998–2001 were respectively, 2,500,