Cowpea is a legume with an annual growth cycle, native to Africa but widely cultivated today not only on its continent of origin but also in Southeast Asia, Central and South America, as well as the southern parts of the United States. It is also known as niebe, lubia, coupe, frijole, blackeye pea, crowder pea or southern pea. It was linked for thousands of years to the cereal farming in West Africa, being grown alongside pearl millet and sorghum since ancient times. Cowpea has multiple uses, it can be a food crop, a vegetable or it can be fed to animals. Its good nutritive content makes it valuable in the diet of both humans and animals.
It is an annual herbaceous legume, which grows during the warm part of the year. Cultivated types exhibit many variations in their characteristics. The plants can be fully erect, partially erect, climbing or trailing on the ground. The growth patterns are also variable and can be very determinate in climbing types and indeterminate in others. Roots tend to be extremely vigorous and the taproot depth can reach 95 inches in just 8 weeks of growth.
Leaves are alternate, with a trefoil shape and a smooth appearance. They rarely reach full maturity, can be either shiny or dull and very widely vary in both size and shape. Normally, the leaflet at the end is bigger and longer than the ones found on the sides.
This is a day-neutral plant that will generally produce flowers regardless of the exposure to light cycles. From the leaf axils emerge several peduncles, each with multiple racemes with flowers. Usually, every peduncle has 2-3 flower pods but sometimes even more can be found on one. The length of the peduncles, between 8 and 20 inches, is very useful in cultivation because makes it easier to gather them. Cowpeas are normally self-pollinating but still attract numerous insects. These are drawn in by nectar which is easily accessible, the flowers being open and located on top.
Pods are also quite long, between 6 and 10 inches, with a cylindrical shape. They have a slight curve, while the color is usually an indicator of ripeness. Depending on the variety, cowpea pods can be yellow or purple when ready for harvest, although in some cases they remain green. Later, the seeds dry out completely and their pods turn darker, becoming brown or tan.
Seeds can be small in wild plants but tend to be much bigger in cultivars and can even reach a record length of 14 inches. The shape of the seeds depends on the environment, if constrained by the pod walls they grow in a rounder shape. If free, seeds will grow unrestricted and eventually look like small kidneys. Seeds display numerous variations in color and the aspect of their outside skin. The color ranges from white to black with all the other nuances in between, like green, buff, red, brown or cream. Their coats can be straight or more or less wrinkled, while the seeds are sometimes speckled. When the seeds have a white hilum, while the rest is a different color, they resemble an eye and have characteristic popular names such as pinkeye purple hull, blackeye and so on.
Like the common bean and the lupin, cotyledons grow from the ground during germination. This type of sprouting is known as epigeal in scientific terms but can be a problem in cultivation since seedlings are vulnerable to damage. The buds located under the cotyledonary node do not regenerate.
Cowpeas are a major source of vegetable protein, in particular amino acids, lysine and tryptophan. While the protein content is higher than in cereals, cowpeas lack the methionine and cysteine found in meat proteins. They can be used as a protein supplement for a cereal-based diet and as a complementary protein source besides animal ones.
As a vegetable crop, cowpeas can be eaten in all stages of development. Africans prepare the fresh green leaves similar to spinach, in pot dishes, which is a very popular food in the area. Raw pods are eaten and prepared like snap beans and serve as ingredients in numerous types of food. Both the green and the dry seeds are edible, while the green ones can be boiled and consumed fresh, both varieties can be canned, frozen or boiled.
Cowpea is very important as animal fodder. Actually, in many regions it is the only legume that provides top quality hay for livestock. It is even on par with alfalfa, regarding production and nutrients, and some cultivars have been developed specifically as fodder, being usable as both green and dried. Because of its strong roots, the plant can also stop erosion and fix nitrogen in the ground. It must also be said that cowpea includes trypsin inhibitors which reduce the utilization of protein, like other grain legumes.
Many people are affected by digestive issues, which can be very uncomfortable. Diarrhea or constipation can severely affect productivity and are usually embarrassing. Cowpeas are a very rich source of fiber, which can solve most of these problems when included in the daily meals. Fibers absorb water and add bulk to the stool, boost peristaltic motion and make digestion more effective so that an increased amount of nutrients are absorbed. This regulates digestive movements and helps with a wide range of stomach issues.
Lately, researchers from all over the world have turned their sights on the antioxidants found in cowpeas. During metabolism, our bodies produce free radicals, which are extremely dangerous to health since they react with nearby tissues. Antioxidant compounds can neutralize them, eliminating this hazard. Cowpeas have been known for a long time to decrease the risk of cancer and other chronic diseases, due to their antioxidant content. It is believed that the vitamins A and C alone can fight toxins and boost the immune response.
Another key vitamin found in cowpeas that has been a focus of modern research is thiamine, or vitamin B1. This vitamin appears to be able to protect the heart, decreasing the risk of heart failure and regulating the ventricles. Other compounds found in cowpeas, such as several types of flavonoids, boost this effect by their anti-inflammatory properties, allowing the heart to function optimally. This is further enhanced by the dietary fibers, which reduce the levels of cholesterol, unclogging arteries and protecting against strokes and heart attacks.
Cowpeas can also assist in sleep disorders. They contain an important dose of tryptophan, which modulates sleep and relaxes the mind. People who suffer from insomnia or irregular sleep can replace their sleeping pills with a bit of cowpeas salad during the evenings, just a few spoons are enough for a relaxing rest.
Bioactive mineral with an influence on sleep is magnesium. Cowpeas are rich in this metal, which has been overlooked for a long time but is now considered very important because it can fight stress and is one of the building blocks of bones. In addition, magnesium is a key element in the assimilation of carbohydrates and can regulate blood sugar levels even in unhealthy diets.
The high level of iron in cowpeas is well-known, the beans have been used to counter anemia even in ancient medicine. Anemia is actually started by a lack of iron, which causes excessive weakness and fatigue but also more severe problems like confusion, stomach pain or a dysfunctional metabolism. Iron is also the main component of red blood cells, more iron means more cells, which in turn transport more oxygen to all parts of the body. As a result, all organs work well, the overall level of energy is increased and the rate of healing is boosted. Eating cowpeas not only fights anemia but improves circulation as well.
Being low in fats, calories and especially cholesterol, but rich in proteins and dietary fibers, cowpeas are an excellent choice for a healthy diet and help in weight loss. This is not only due to the nutritive content, since a better digestion actually ensures nutrients are used, rather than being deposited as fat. In addition, fibers make you feel full and less hungry. This eliminates the main problem in weight loss diets, which is the temptation to have a snack between meals caused by a sensation of hunger, which can happen very often if not enough fibers are eaten.
Cowpeas are also great for a healthy skin, because of the powerful combination of proteins, antioxidants and vitamins A and C. They do not only improve the health of the skin, but its appearance as well. Proteins are essential to allow the damaged cells to regenerate and for new tissues to grow. At the same time, antioxidants shield the skin from destructive direct sunlight and allow the faster healing of scars, eliminating irritation and the effects of aging.
