LEGUMES. Legumes are members of a family of flowering plants known as Leguminosae. It is one of the three largest families of flowering plants, with approximately 690 genera and about 18,000 species. Legumes are a significant component of nearly all terrestrial biomes on all continents except Antarctica. Some are fresh water aquatics, but no truly marine species exist. The species within the family range from dwarf herbs among arctic and alpine vegetation to massive trees in tropical forests.
The leaves usually occur alternately on the stem and are compound, meaning each leaf is divided into separate leaflets. Both pinnate and trifoliate leaves exist. Legumes are easily recognized by the structure of the flower. The flowers are hermaphroditic with male (stamens) and female (pistils) parts in the same flower and usually with five sepals and five petals. The ovary has a single carpel, cavity, and style. The principal unifying feature of the family is the fruit, a pod technically known as a legume. The legume pod is modified in many ways, including flat, winged, thick, thin, straight, coiled, short, long, woody, fleshy, splitting open, or indehiscent to facilitate dispersal by animals, wind, and water.
The family is divided into three subfamilies: Papilionoideae, Caesalpinioideae, and Mimosoideae, identified by their flowers. The Papilionoideae is the largest of the three subfamilies and the most widespread, extending farther into temperate regions. This subfamily can be easily recognized by its butterfly-like flowers. Most of the important legume crop species consumed by humans, including soybean, field pea, chickpea, field bean, and peanut, are in this group.
The subfamily Caesalpinioideae is comprised of tropical or subtropical trees and shrubs. The useful products derived from this subfamily include edible fruits (Tamarindus indica), senna medicine (Senna spp.), hematoxylon red dye from the logwood tree (Haematoxylon campechianum), and resins used in paints, varnishes, inks, plastics, adhesives, and fireworks derived from the copal (Copaifera spp.) tree.
The subfamily Mimosoideae includes species of industrial, forage, browsing, and fodder importance, such as Acacia spp. (Bisby et al., 2000). The Australian black-wood (Acacia melanoxylon) tree provides useful timber, and gum arabic from the tree of that name (Acacia senegal) is used in an array of industrial processes.
Most legumes convert atmospheric nitrogen into nitrogenous compounds useful to plants. Root nodules containing Rhizobium bacteria fix free nitrogen for the plants. In return, legumes supply the bacteria with carbon produced by photosynthesis. This symbiosis provides the nitrogen needed by the plants for survival. Root nodules form in all subfamilies except in rare cases among the Caesalpinioideae.
The basic process of nitrogen fixation involves penetration by the Rhizobium through the root hairs into the cortex, where cell division occurs. These tetraploid cells produce the nodules that appear on the root surface. The nodule growth and efficiency are influenced by the carbon-nitrogen ratio of the plant and by the presence in the soil of phosphate, calcium, magnesium, molybdenum, and boron. If the nodules are ineffective, the bacteria may be parasitic on the host plant. Effective nodules contain red leghemoglobin, which can be seen when the nodules are cut. Ineffective nodules are usually small, hard, spherical, and a greenish color inside. Legumes produce more nodules in the tropics in acid soils and soils deficient in phosphorus, calcium, and other nutrients than in temperate areas. Many strains of Rhizobium occur in nature with multiple hosts, and several Rhizobium species occur with one host (Purseglove, 1981). Many scientists suggest inoculating legume seeds with the appropriate strain of Rhizobium for best agricultural results. This inoculation technique is accomplished by mixing the Rhizobium in water to form a slurry and then adding it to the seed.
The primary temperate legumes used for human food include garden pea (Pisum sativum), field pea (Pisum arvense), winged pea (Tetragonolobus purpureus), green bean (Phaseolus vulgaris), runner bean (Phaseolus coccineus), butter bean (Phaseolus lunatus), lima bean (Phaseolus limensis), soybean (Glycine max), lentil (Lens culinaris), and broad bean (Vicia faba). These legumes originated in humid, subhumid, cool season, subtropical, semiarid, and temperate areas in diverse regions ranging from Southwest Asia and East Asia to the Mediterranean, Peru, Mexico, and Guatemala (Muehlbauer, 1993).
Common tropical legumes consumed by humans include winged bean (Psophocarpus tetragonolobus), jicama (Pachyrhizus erosus and Pachyrhizus tuberosus), chickpea (Cicer arietinum), black-eyed pea (Vigna unguiculata unguiculata), and peanut (Arachis hypogaea). These tropical legumes originated in areas characterized by humid, semiarid, cool season, subtropical, and tropical climates, primarily including South America, Southwest Asia, Ethiopia, India, Japan, China, and West Africa (Hymowitz, 1990).
History. Soybean, one of the most popular legumes, is one of the oldest cultivated crops. Cultivated soybeans probably arose from a wild type in Asia and moved to Europe and North America in the eighteenth century. Soybean soon became the third most important agronomic crop in the United States. Cowpeas were introduced to the West Indies and ultimately spread throughout the southern United States after the seventeenth century. Field beans (Phaseolus spp.) were cultivated by American Indians at the time of the European discovery of North America and soon were introduced to Europe. The popular peanut, introduced into the United States from Brazil when the colonies were established, was commercially developed in the mid-eighteenth century.
Peas, including garden peas, field peas, broad beans, lentils, and chickpeas, were introduced into the Americas from Europe and the Near East. Jicama is grown in Southeast Asia, Mexico, and Central America. Winged beans were introduced into more than sixty countries, primarily subtropical and tropical, after the mid-1970s.
Primary Food Legumes
Soybean (Glycine max). Soybean is the most important legume produced in the agricultural industry worldwide. It is an annual crop, is easy to grow, and is adapted to a temperate climate. A hot weather crop, soybean requires a minimum of 59°F (15°C) for seed germination and mean temperatures of 68–77°F (20°–25°C) for crop growth. Only moderate soil moisture is needed for germination and seedling establishment, but dry weather is essential for dry seed production. Soybeans suffer when the soil is waterlogged, and established plants tolerate drought.
Soybeans should be fertilized with phosphorous, potassium, and micronutrients, and they require typical agricultural field preparation. The important differences among soybean cultivars are day-length response, pest resistance, and production. These varieties are subdivided into groups according to tropical, subtropical, or temperate climate adaptation (Martin, 1988).
Several major obstacles obstruct optimum soybean production. Diseases cause one-eighth of all soybean losses. Noteworthy diseases and their causal agents include bacterial blight (Pseudomonas glycinea), bacterial pustule (Xanthomonas phaseoli var. sojense), and wildfire (Pseudomonas tabaci). However, the most devastating diseases are caused by fungi, including brown stem rot (Cephalosporium gregatum), stem canker (Diaporthe phaseolorum var. batatatis), pod and stem blight (Diaporthe phaseolorum var. sojae), brown spot (Septoria glycines), and sclerotial blight (Sclerotium rolfsii). Mosaic virus disease, root knot nematode (Meloidogyne spp.), and cyst nematode (Heterodera glycines) also cause significant soybean losses.
The chemical composition of mature soybeans varies with the cultivar plus the soil and climate conditions. Generally, the black-seeded cultivars are protein rich with low oil content, and the yellow-seeded types are oil rich with low protein. The nutritional components of dried seeds are 5.0 percent to 9.4 percent water, 29.6 percent to 50.3 percent protein, 13.5 percent to 24.2 percent fat, 14.0 percent to 23.9 percent carbohydrate, 2.8 percent to 6.3 percent fiber, and a large amount of vitamin B. Soybean seeds contain a higher amount of protein than any other pulse and most other foodstuffs.
Soybean oil is about 51 percent linoleic acid, 30 percent oleic acid, and 6.5 percent linolenic acid and is used as a cooking oil, salad oil, shortening, and margarine. Soybean flour is mixed with wheat flour in baked products, such as bread, cakes, cookies, and crackers, and it is also used in ice cream, candy, and pudding. In Asia soybeans are consumed as soybean milk, soy sauce, soups, drinks, breakfast foods, and vegetables. People in eastern Asia eat unripe seeds and dried seeds, and elsewhere these large seeds are consumed as shelled green beans or as dry beans. Both the Bansei and the Green Giant cultivars are among the more popular soybeans. In the West soybeans are a primary ingredient of Worcestershire sauce, made by mixing boiled beans with wheat flour and salt, then fermenting the mixture with the fungus Aspergillus oryzae for up to one week. The fermented beans are submerged in brine and exposed to the sun for several months to extract the flavor. In Indonesia boiled beans are fermented with Aspergillus and formed into cakes.
Soybeans are used industrially in paints, linoleum, inks, soaps, insecticides, and disinfectants. Soy meal, the residue of oil extraction, is a healthy livestock feed (Purseglove, 1981). Soybeans are also used in the pharmaceutical and nutraceutical industries. For example, Ensure glucerna, a dietary aid for diabetics, includes soybeans, and Estroven, marketed as a dietary supplement with natural phytoestrogens, contains isoflavones, a group of antioxidants found in both humans and legumes, extracted from soybeans. While isoflavones do not show antioxidant activity in legumes, they serve various roles as protectants, attractants, and repellents. Because of their antioxidant characteristics, it is possible that isoflavones make a healthy contribution to the human diet.
Groceries and other retail stores sell products that contain soybeans in some form, and American and Oriental restaurants offer foods with soybean constituents. In addition, many products sold as dietary supplements or nutraceuticals in health food stores include soybeans.
Field peas (Pisum arvense and Pisum sativum). The green pea type of field pea became a food source in the sixteenth century. Field peas grow during the cool season and develop flowers and seeds as the days become longer. Field peas have a variety of uses, and production has increased worldwide. At the beginning of the twenty-first century, U.S. production was estimated at 200,000 hectares, and Canadian production exceeded that threefold. Major diseases include Ascochyta blight (Ascochyta pisi and Ascochyta pinodella), bacterial blight (Pseudomonas pisi), and fusarium wilt (Fusarium oxysporum f. pisi). Significant insect pests are the pea weevil (Bruchus pisorum), the pea aphid (Illinoia pisi), and particularly the root knot nematode (Meloidogyne incognita). The wrinkled-seed types of field peas are canned in the immature stage, and the smooth-seed types are eaten as dried peas.
Field peas are usually grown as winter annuals in regions receiving 450 to 500 millimeters of rainfall annually. Generally, field peas perform best on well-drained soils with pH between 6.0 and 7.5. Nitrogen fertilization is not needed, but phosphorus, potassium, and sulfur are required (Muehlbauer, 1993).
The nutritional components of dried seeds are 10.6 percent water, 22.5 percent protein, 1 percent fat, 58.5 percent carbohydrate, and 4.4 percent fiber. Fresh green peas are about 74.3 percent water, 6.7 percent protein, 0.4 percent fat, 15.5 percent carbohydrate, and 2.2 percent fiber. These legumes are a major source of human dietary protein worldwide but are of minor importance in the United States. The seeds are consumed as a fresh vegetable and are canned, frozen, and dried. Field pea pods are also edible. Worldwide field pea plants are used for forage, hay, silage, and green manure (Purseglove, 1981).
Field beans (Phaeolus spp. ). Brazil, the United States, Mexico, and Italy are the leading producers of field beans. In the United States the common field bean is grown primarily in New York, Michigan, and west of the Mississippi River. Suitable for a variety of soil types, beans are a warm season annual crop. The optimum temperature is 63–77°F (17–25°C), and the beans need 120 to 130 days without frost.
Field bean crops require fertilization with phosphorus and potassium, and zinc is often needed in residual amounts. Because beans are planted in warm soil after all danger of frost is past, planting dates vary from early April to early July according to geographic location. Dry beans are harvested after the pods turn yellow and prior to seed scattering (Martin and Leonard, 1967). Field beans are subject to a wide array of diseases, including bacterial blight (Xanthomonas phaseoli), anthracnose (Colletotrichum lindemuthianum), and common bean mosaic virus. Insect pests that cause substantial damage and loss are the bean weevil (Acanthoscelides obtectus) and the Mexican bean beetle (Ephilachna varivestris).
Rich in the amino acids lysine and tryptophane, field beans are one of the most important sources of human dietary protein. Dried adzuki beans (Phaseolus angularis), consumed in Japan and China in soups and cakes, are about 21 percent to 23 percent protein, 0.3 percent fat, and 65 percent carbohydrate. Mung beans (Phaseolus aureus) are about 9.7 percent water, 23.6 percent protein, 1.2 percent fat, 58.2 percent carbohydrate, and 3.3 percent fiber. The green mung bean pods are edible, and the fried seeds are popular in India (Purseglove, 1981). Flour from the seeds is used in Indian and Chinese foods, and in the United States grocery chains and restaurants offer mung bean sprouts. Rice beans (Phaseolus calcaratus) are consumed in India, Burma, Malaysia, China, Fiji, and the Philippines. The beans are usually boiled, and the young pods and leaves are also eaten. Rice beans are about 10.5 percent water, 21.7 percent protein, 0.6 percent fat, 58.1 percent carbohydrate, and 5.2 percent fiber.
Central Americans consume the green and dried seeds of the scarlet runner bean (Phaseolus coccineus). Lima or butter beans (Phaseolus lunatus) are eaten fresh, canned, or frozen in the United States. Dried lima beans are 12.6 percent water, 20.7 percent protein, 1.3 percent fat, 57.3 percent carbohydrate, and 4.3 percent fiber. However, the green beans contain about 66.5 percent water, 7.5 percent protein, 0.8 percent fat, 22.0 percent carbohydrate, and 1.5 percent fiber. The mature beans contain the glucoside phaseolutanin, which gives them their characteristic taste. Because the seeds contain hydrocyanic acid, the cooking water should be boiled and changed during preparation to dissipate the acid.
Black grams (Phaseolus mungo) are highly prized in vegetarian diets in India. They can be boiled or eaten whole, and they are ground into a flour used to make porridge or baked into bread and biscuits. The green pods are also edible. Dried black grams are about 9.7 percent water, 23.4 percent protein, 1.0 percent fat, 57.3 percent carbohydrate, and 3.8 percent fiber (Purseglove, 1981).
The most popular and most widely used beans are known as French beans, kidney beans, runner beans, snap beans, and string beans and are sold throughout the world in grocery stores and restaurants. These are the primary protein food in Latin American and tropical Africa, and in Europe and the United States they are grown for the immature pods, which are consumed fresh, canned, and frozen. The popular baked beans are made with any of these types of whole dried beans cooked with tomato sauce.
Winged bean (Psophocarpus tetragonolobus). The winged bean is a perennial vine that climbs by twining. Usually grown as annuals, the plants flower during short days. Scarifying winged bean seeds induces better germination. Seeds are planted anytime during the year and germinate within five to fifteen days. The plants tolerate various soil types, including heavy, poorly drained, riverbank, sandy, and infertile soils. Organic material in soil promotes successful winged bean growth; otherwise a small amount of mineral fertilizer is generally recommended. While few pests attack winged beans, geese and chickens consume the plants, and damage by cowpea aphids and root knot nematodes has been reported (Martin and Delpin, 1978).
Winged bean leaves, flowers, shoots, immature pods, mature dried seeds, and tubers, which are highly nutritious, are primarily consumed in Papua New Guinea, South Asia, and Southwest Asia. The young, tender pods, sliced or chopped, are eaten raw. The mature dried seeds are especially nutritious because of their high protein content, 30 to 42 percent. These mature seeds can be steamed, boiled, fried, roasted, or made into milk or tofu. The beans contain some antinutritional substances, thus the seeds should always be soaked overnight and then boiled in water until tender. Oil derived from winged beans contains behenic acid, linoleic acid, and tocopherols (vitamin E). Behenic acid reduces the digestibility of winged beans. Tocopherols are antioxidants that improve the utilization of vitamin A in the human body.
Winged bean tubers, which have a protein content of 8 to 20 percent, are eaten boiled, steamed, fried, or baked in Burma and Papua New Guinea. Winged bean sprouts and shoots are consumed raw or cooked. Usually only the top three leaves are eaten. The flowers, steamed or fried, taste similar to mushrooms. The seeds contain several antinutritional phytochemicals, such as trypsin and chymotrypsin inhibitors, amylase inhibitors, phytohemagglutinins, and cyanogenic glycosides. The seed inhibitor activity can be safely eliminated only by moist heat, that is, by soaking the seeds for ten hours and then boiling them for thirty minutes. Both vanilla-and chocolate-flavored milks have been produced from the seeds in Thailand. Scientists have developed snacks of the tubers sliced thin, fried, and salted or softened in sugar syrup. Immature winged bean pods are pickled in southern India (Martin and Delpin, 1978). Psophocarpus tetragonolobus lectin is derived from winged bean seeds and is used commercially in medical diagnostics.
Jicama (Pachyrhizus erosus and Pachyrhizus tuberosus). Jicama is a tuberous legume commonly grown in Mexico on commercial farms and intercropped with maize and beans on smaller farms. It is also monocropped in Thailand, Malaysia, and Hawaii. Jicamas are usually grown from seeds, however, sprouted tubers are occasionally used. In Mexico tuber yields are highest when planted in March and harvested from September to November, and in Hawaii maximum tuber yields occur when planted in September or October and harvested five months later. Thus jicamas require a hot subtropical to tropical climate with moderate rainfall. They tolerate some drought but are sensitive to frost. They attract few pests but occasionally are attacked by the rose beetle (Adoretus versutus) and the bean common mosaic virus (Grum, 1990).
The edible portion of jicamas are about 87.1 percent water, 1.2 percent protein, 0.1 percent fat, 10.6 percent carbohydrate, and 0.7 percent fiber. The tubers are eaten raw or cooked. The young pods from Pachyrhizus erosus are prepared like French beans, but the mature seeds and roots of that plant contain a toxic substance known as rotenone. Young pods of Pachyrhizus tuberosus are avoided because they have irritant hairs (Purseglove, 1981).
Chickpea (Cicer arietinum). Chickpea is the major pulse crop in India, where production reaches 7 million hectares. In the United States, chickpeas are primarily grown in California, Washington, and Idaho. These legumes have a high phosphorus requirement, and both potassium and sulfur should be added if the soil is deficient in either. Chickpeas are adapted to dry conditions and generally flourish on well-drained soils of pH 6.0 to 7.5. The major chickpea pests include gram blight (Mycosphaerella rabiei), rust (Uromyces ciceris-arietini), wilt (Rhizoctonia bataticola and Fusarium orthoceras), and gram caterpillar (Heliothis armigera).
Chickpeas are important in India, where the dried seeds are boiled and the green pods and shoots are prepared in a variety of ways. Flour made from chickpeas is used in many Indian confections. The common chickpea, also called garbanzo bean, is used in the United States primarily in salads and as a vegetable side dish. Dried chickpeas are about 9.8 percent water, 17.1 percent protein, 5.3 percent fat, 61.2 percent carbohydrate, and 3.9 percent fiber (Purseglove, 1981).
Peanut (Arachis hypogaea). Peanuts, called groundnuts in other parts of the world, are one of the most important crops in the southern United States, primarily in Georgia, Texas, Oklahoma, North Carolina, Alabama, and Virginia. Other leading production countries include India, China, Nigeria, Senegal, Indonesia, and Brazil. An annual crop with a growing season from 1 May to 1 November in the United States, the peanut prefers sandy loam soils. Adequate soil moisture and high temperatures are necessities for seed germination and plant growth. Peanuts respond best when the pH is above 5. The American peanut is classified into three botanical types based on the shape of the nut and growth characteristics: Virginia (bunch and runner growth types), Spanish (bunch growth type), and Valencia (bunch growth type). Crop rotation is recommended because peanut yields are good following cotton or other nonleguminous crops, and applications of lime and potash usually increase yields. Peanuts suffer from cercospora leaf spots (Cercospora arachidicola and Cercospora personata), stem and peg rots (Sclerotium rolfsii), and tomato spotted wilt virus.
Peanuts are consumed by humans throughout the world as peanut butter, in candies, and as cooking oil. Peanut oil is about 53 percent oleic acid and 25 percent linoleic acid. The Virginia peanut is 38 percent to 47 percent oil, and the Spanish peanut is 47 percent to 50 percent oil. Shelled peanuts are about 5.4 percent water, 30.4 percent protein, 47.7 percent fat, 11.7 percent carbohydrate, and 2.5 percent fiber. The primary proteins in peanuts are arachin and conarachin, and peanuts are rich in vitamins B and E (Pattee and Young, 1982). Some people have allergenic reactions to certain types of peanuts. The peanut allergens designated as Ara h 1, Ara h 2, and Ara h 3 are glycoproteins with a molecular mass of 63 kilodaltons and are present in raw and roasted peanuts since they are heat stable and may be found in any peanut type. Peanut proteins, including arachin, conarachin, peanut agglutinin, and peanut phospholipase, can also be allergens. Other important phytochemicals in peanuts are protocatechuic acid, which has shown potential antioxidant and pesticidal qualities, and lecithin, which has shown antioxidant activity (Beckstrom-Sternberg and Duke, 1994). A lectin derived from peanuts is used commercially in medical diagnostics.
Cowpea (Vigna spp. ). Cowpeas led U.S. legume production until about 1941, when they were replaced by soybeans, clovers, and other special-purpose legumes. Cowpeas are produced in California on a fairly large scale, and they are cultivated in Africa, southern Asia, and the Mediterranean region of Europe. A short-day, warm-weather crop, they should be planted in warm soil after all danger of frost has passed. However, severe drought will prevent seed formation. Cowpeas grow well in sandy or clay soils with good water drainage. The common black-eyed pea (Vigna unguiculata) is by far the most important cowpea variety.
Common diseases include cowpea wilt (Fusarium oxysporum var. tracheiphilum), cowpea root knot nematode (Meloidogyne spp.), charcoal rot (Macrophomina phaseoli), and viral diseases. The chief insect problems are the cowpea weevil (Callosobruchus maculatus) and the southern cowpea weevil or four-spotted bean weevil (Mylabris quadrimaculatus).
Legumes Cultivated for Phytochemicals
Jack beans (Canavalia ensiformis) are cultivated primarily for their phytochemicals. The ripe, dried seeds are about 11.0 percent water, 23.4 percent protein, 1.2 percent fat, 55.3 percent carbohydrate, and 4.9 percent fiber (Purseglove, 1981). Jack bean seeds are the only source of the lectin known as concanavaline-A, which is used in medical diagnostics. Lectins extracted from several other legumes, including sunn hemp (Crotalaria juncea), red kidney beans (Phaseolus vulgaris), and field peas (Pisum sativum), are used in medical diagnostics also. Guar seeds (Cyamopsis tetragonolobus) contain galactomannan gum, which is used in food additives; industrials; pharmaceuticals; confectionaries, including cereal, ice cream, and candy (Whistler and Hymowitz, 1979); and nutraceuticals, such as Ensure glucerna.
Kudzu (Pueraria spp.) produces isoflavones used in nutraceuticals for natural estrogen therapy, such as Estroven. A nutraceutical known as kudzu root is sold in powder form. Velvet bean (Mucuna pruriens) extract is
|Minor legumes with special-purpose value|
|Canavalia ensiformis (L.) DC.||Jack bean||Forage, green manure, pulse||Pesticide||Concanavalin-A (lectin)|
|Crotalaria juncea (L.)||Sunn hemp||Paper, green manure||Bactericide, pesticide||Pectin (antidiabetic, antidiarrhetic, antitumor, antiulcer, cancer preventive)|
|Mucuna pruriens (L.) DC.||Velvet bean||Green manure||Bactericide, pesticide, viricide||Beta-sitosterol (anti-inflammatory, antileukemic, antitumor, cancer preventive, estrogenic)|
|Gallic acid (antioxidant, antiseptic, antiviral, cancer preventive)|
|Lecithin (anti-Alzheimeran, hepatoprotective)|
|Rhynchosia minima (L.) DC.||Snout bean||Forage||Fungicide, pesticide, viricide||Gallic acid (see above)|
|Protocatechuic acid (antiasthmatic, antioxidant)|
|Senna occidentalis (L.) Link||Coffee senna||Bactericide, pesticide, viricide||Tannin (antidiarrhetic, antioxidant, antiviral, cancer preventive)|
|Tephrosia purpurea (L.) Pers.||Pesticide||Rutin (antidiabetic, anti-inflammatory, antioxidant, antitumor, antiviral, cancer preventive)|
marketed as an antiparkinsonian herbal supplement or nutraceutical. See Table 1 for additional legume phytochemicals.
Legumes Cultivated for Animal Food
Legume species used for forage include Aeschynomene, Desmodium, Leucaena, Macroptilium, Neonotonia, Stylosanthes, Desmanthus, Macrotyloma, Sesbania, and Trifolium. Several species, including Desmanthus virgatus, Stylosanthes scabra, and Stylosanthes guianensis, have been tested in the southeastern United States for possible forage production. Stylosanthes hamata, Stylosanthes humilis, Macroptilium atropurpureum, Macroptilium bracteatum, Neonotonia wightii, and Lotononis bainesii are grown successfully as pasture legumes in Australia and show potential for use in the United States (Morris, 1997).
Other Uses for Legumes
Several legumes have multiple uses as human foods, animal feeds, ornamentals, cover crops, green manure, and erosion control plants. Minor legumes used primarily for cover crops, forage, and green manure worldwide include calopo (Calopogonium mucunoides), centro (Centrosema pubescens), and tropical kudzu (Pueraria phaseoloides) (Morris, 1997).
Indigofera arrecta was once cultivated in India for indigo dye, but it declined significantly with synthetic dye production. In Central Africa, however, indigo dye derived from the plant is still used. Dhaincha (Sesbania bispinosa) produces galactomannan gum and is grown also for soil improvement, fiber for paper pulp, fodder, and its ornamental qualities. Lead trees (Leucaena leucocephala), similar in growth to mimosa trees, are used for paper products and as cover crops, fodder, pastures, green manure, and ornamentals (Morris, 1997). Other legumes are important in reclamation of mined soils, polluted soils, deforested areas, and soils with poor nutritional conditions (Morris, 1997).
The expression "blackball" comes from the ancient Greek and Roman practice of using beans for voting. A white bean signifies acceptance, while a black bean means rejection. The black-eyed pea is eaten on New Year's Day in the southern United States to bring good luck for the coming year.
The Navaho-Ramah Indian tribe used an annual clover known as Trifolium dubium as a ceremonial medicine. For a dermatological remedy the Iroquois used a wild bean known as Strophostyles helvola, and the Pawnees used spider bean (Desmodium illinoensis). Bush clover or rabbit foot (Lespedeza capitata) was an antidote in the Fox tribe and an analgesic for the Omahas and Poncas. The Cherokees chewed tickseed or trefoil (Desmodium
|Ethnobotanical uses of minor legumes|
|Scientific name||Common name||Uses||Countries|
|Canavalia ensiformis (L.) DC.||Jack bean||Kidney and tonic||China|
|Clitoria ternatea (L.)||Butterfly pea||Arthritis||Philippines|
|Crotalaria juncea (L.)||Sunn hemp||Psoriasis||Iraq|
|Crotalaria retusa (L.)||Rattle box||Fever||Java|
|Desmodium adscendens (Sw.) DC.||Tick clover||Bronchitis, colic, ringworms, wound||Africa|
|Desmodium gangeticum (L.) DC.||Dysentery, fever, tonic||India|
|Indigofera tinctoria (L.)||Common indigo||Fever, inflammation, laryngitis, mumps, scabies, swelling, dysentery||China|
|Leucaena leucocephala (Lam.) de Wit||Lead tree||Fever, typhoid||Bahamas|
|Mucuna pruriens (L.) DC.||Velvet bean||Scorpion antidote, asthma, snake bite, cancer, coffee, cough, diarrhea, mumps, ringworms, syphilis, tumor||India, Venezuela, Mexico|
|Psophocarpus tetragonolobus (L.) DC.||Wing bean||Boil, tumor||Java|
|Tephrosia candida DC.||White tephrosia||Insecticide, piscicide||India, Java|
|Tephrosia cinerea (L.) Pers.||Fever, piscicide, venereal, tumor||Mexico, Guiana, Brazil, Venezuela|
|Tephrosia purpurea (L.) Pers.||Colic, piscicide||Sudan, Guiana, Mexico|
|Tephrosia vogelii Hook. f.||Fish poison bean||Insecticide, insect repellant, piscicide||India, Tanzania, Sudan, Africa|
perplexum) roots for sore gums and mouths. The Mohegans made a blood purifier from rattle box (Crotalaria sagittalis) root, and the Delawares treated venereal disease with rattle box root (Beckstrom-Sternberg, Duke, and Wain, 1994). See Table 2 for additional ethnobotanical and multicultural uses of legumes.
See also Nuts; Peanut Butter; Peas.
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Pattee, Harold E., and Clyde T. Young, eds. Peanut Science and Technology. Yoakum, Tex.: American Peanut Research and Education Society, 1982.
Purseglove, J. W. "Leguminosae." In Tropical Crops: Dicotyledons. 2 vols. New York: Wiley, 1987.
Whistler, Roy L., and Theodore Hymowitz. Guar: Agronomy, Production, Industrial Use, and Nutrition. West Lafayette, Ind.: Purdue University Press, 1979.
Biome —The world's major communities classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment
Carpel —A single member of a compound seed-bearing flower organ.
Cortex —The primary plant tissue between the vascular system and the epidermis of the stem and the root.
Cover crop —A crop grown between orchard trees or on fields between cropping seasons to protect the land from leaching of nutrients and erosion.
Diversity —Variety of life on the planet.
Fodder —Coarse plants harvested whole and cured in an erect position.
Forage —Plant matter, fresh or preserved, gathered and fed to animals.
Green manure —Any crop or plant grown and incorporated into the soil.
Hay —Fine-stemmed plants cut and cured for forage.
Heme —Iron-protoporphyrin IX, a ubiquitous prosthetic group structurally associated to many enzymatic, regulatory, transport, and binding proteins.
Herbivorous— Animals that consume only plant material.
Indehiscent —Remaining persistently closed.
Lectin —Proteins or glycoproteins of nonimmune origin that agglutinate cells and precipitate complex carbohydrates. They are valuable for blood grouping and erythrocyte polyagglutination, mitogenic stimulation of lymphocytes, lymphocyte subpopulation studies, fractionation of cells and other particles, and histochemical studies of normal and pathological conditions.
Leghemoglobin —Heme-containing, oxygen-binding protein found in plants.
Ovary —The part of the pistil (the seed-bearing flower organ) that contains the ovules.
Parasitic —An organism living or feeding on another organism to the detriment of the host organism.
Pasture —Land with forage plants used for grazing animals.
Petal —A division of the corolla (the inner floral envelope).
Pinnate leaf —Compound leaf with leaflets arranged on each side of a common axis.
Pulse —Legume plants or seeds used for food.
Sepal —A division of a calyx (the outer floral envelope).
Silage —Forage preserved in a succulent condition by partial fermentation in a tight container.
Style —The portion of the seed-bearing flower organ that connects the stigma and the ovary.
Tetraploid —An organism whose cells contain four haploid (4n) sets of chromosomes or genomes.
Trifoliate —Having three leaflets.
Uses for Legumes
Senna occidentalis —Potential bactericidal, pesticidal, and viricidal plant. It also contains tannin, which is an antidiarrhetic, an antioxidant, and an antiviral agent and has cancer preventive potential.
Crotalaria juncea —Sunn hemp, known as a multiple-use small-tree crop. It is used in paper making and as green manure and has bactericidal qualities. Sunn hemp contains pectin, which has antidiabetic, antidiarrhetic, antitumor, antiulcer, and cancer preventive potential. Sunn hemp has been used in Iraq to treat psoriasis.
Mucuna pruriens —Velvet bean, a green manure crop and a nutraceutical in the United States. The seeds contain L-dopa, which is used in the treatment of Parkinson's disease, beta-sitosterol, a potential anti-inflammatory, antileukemic, antitumor, cancer preventive, and estrogenic agent; gallic acid, a potential antioxidant, antiseptic, antiviral agent, and cancer preventive; and lecithin, a potential Alzheimer's preventive. Velvet bean is also used in India, Venezuela, and Mexico to treat asthma, snake bites, cancer, coughs, diarrhea, mumps, ringworm, syphilis, and tumors and as a scorpion antidote.
"Legumes." Encyclopedia of Food and Culture. . Encyclopedia.com. (May 22, 2017). http://www.encyclopedia.com/food/encyclopedias-almanacs-transcripts-and-maps/legumes
"Legumes." Encyclopedia of Food and Culture. . Retrieved May 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/food/encyclopedias-almanacs-transcripts-and-maps/legumes
Legumes are the edible seeds of plants. They provide a good source of protein , thiamine, folic acid, vitamin E, and fiber . The insoluble fiber in legumes helps to lower blood cholesterol . Examples of legumes are: dried beans, peas, and seeds (including navy, broad, butter, northern, pinto, red, and black beans, as well as chick peas, soybeans, and peanuts).
Legumes are an important source of protein for vegetarians, especially vegans . The protein in legumes is considered incomplete, however, and needs to be eaten in combination with whole grains to make a complete (high-quality) protein (e.g., green beans, lentils, and rice; navy beans and barley; soybeans and sesame seeds; red beans and rice). Such combinations have been used for centuries in the diets of people practicing vegetarianism.
see also Plant-Based Diets; Soy; Vegetarianism.
Simin B. Vaghefi
"Legumes." Nutrition and Well-Being A to Z. . Encyclopedia.com. (May 22, 2017). http://www.encyclopedia.com/food/news-wires-white-papers-and-books/legumes
"Legumes." Nutrition and Well-Being A to Z. . Retrieved May 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/food/news-wires-white-papers-and-books/legumes
legume (lĕ´gyōōm, lĬgyōōm´), common name for any plant of the family Leguminosae, which is called also the pulse, legume, pea, or bean family. The word is often used loosely in the plural for vegetables in general. Botanically, a legume is the characteristic fruit of the pulse family plants, called also leguminous plants. It is a pod which usually splits along two sides, with the seeds attached along one of the sutures. The family Leguminosae is classified in the division Magnoliophyta, class Magnoliopsida, order Rosales.
"legume." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (May 22, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/legume
"legume." The Columbia Encyclopedia, 6th ed.. . Retrieved May 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/legume
Legumes include the groundnut, Arachis hypogaea, and soya bean, Glycine max, grown for their oil and protein, the yam bean Pachyrrhizus erosus, and African yam bean Sphenostylis stenocarpa, grown for their edible tubers as well as seeds. See also beans.
"legumes." A Dictionary of Food and Nutrition. . Encyclopedia.com. (May 22, 2017). http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/legumes
"legumes." A Dictionary of Food and Nutrition. . Retrieved May 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/legumes
leg·ume / ˈlegˌyoōm; ləˈgyoōm/ • n. a leguminous plant, esp. one grown as a crop. ∎ a seed, pod, or other edible part of a leguminous plant used as food. ∎ Bot. the long seedpod of a leguminous plant. ORIGIN: mid 17th cent. (denoting the edible portion of the plant): from French légume, from Latin legumen, from legere ‘to pick’ (because the fruit may be picked by hand).
"legume." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (May 22, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/legume-0
"legume." The Oxford Pocket Dictionary of Current English. . Retrieved May 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/legume-0
"legume." World Encyclopedia. . Encyclopedia.com. (May 22, 2017). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/legume
"legume." World Encyclopedia. . Retrieved May 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/legume
"legume." A Dictionary of Biology. . Encyclopedia.com. (May 22, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/legume
"legume." A Dictionary of Biology. . Retrieved May 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/legume
"legume." Oxford Dictionary of Rhymes. . Encyclopedia.com. (May 22, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/legume
"legume." Oxford Dictionary of Rhymes. . Retrieved May 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/legume