Legume Family [ Back to top of this page ]
Outside of Africa and Indonesia, few people realize that bean plants produce leaves that are a highly nutritious and tasty potherb eaten throughout Africa and in Indonesia. They are extremely rich in beta-carotene, vitamin C, iron, calcium and protein. Bean leaves are grown in two different ways. When grown as a separate crop it is planted more densely than when grown for beans and the plants are usually uprooted at 3-5 weeks. Sometimes small farmers and gardeners try to combine a harvest of leaves and beans. This is best done by harvesting leaves from the lower third of the plant just before flowering begins.
A very popular boiled green in India called Mehta, fenugreek (literally Greek hay) is an extremely rich source of iron in that largely vegetarian country.
Pigeon pea (Cajanus cajan)
Pigeon pea is native to Africa and ranks sixth in world production of dry legume seeds. It is a short lived perennial that grows up to 12 feet (4 meters) tall and has a deep root system that gives it superior drought resistance. It is rarely used for its edible leaves but could become a more important leaf vegetable in the dry season in much of the tropics.
A climbing short lived perennial native to India. It is used as a forage or green manure crop as well as for its beans. It is a strong nitrogen fixer. The white seeded varieties are much preferred to darker ones as they contain far less toxins (cyanogenic glucoside and trypsin inhibitor). Like pigeon peas, it is rarely used for its edible leaves but could become a more important leaf vegetable.
A small, quick growing shrub or small tree about 20 feet (6 meters) tall with graceful foliage. It is commonly grown throughout much of the tropics and its fruits, flowers and leaves are all edible. In Malaysia the young leaves are stripped from the stalks and lightly boiled or steamed or served as a vegetable in curries.
In the Sudan in Africa, leaves of this leguminous tree are used to make a fermented food called kawal that has great promise as a food in emergency situations. The fresh leaves are pounded to a paste and allowed to ferment. After about 2 weeks, the fermented paste is molded into small balls and then sun-dried. This high-protein preserved ferment is added to spicy stews. All the essential amino acids are present in kawal.
This small leguminous tree grows in arid regions from Africa through south west Asia. It is extremely drought resistant and is being investigated in India as one of the crops that can help reclaim saline ruined farm land. It is a source of gum arabic and its leaves and young pods are cooked as vegetables.
Peas are one of the first plants to be cultivated by humans and are commonly grown throughout the world's temperate and sub-tropical zones. The tender young shoots of the pea plant have a pleasant nut like flavor and make a good salad green or potherb. Austrian winter peas are sometimes used as a cold weather green manure crop to add nitrogen and organic matter to the soil. The young leaves of these plants are excellent in the early spring.
Pumpkin Family [ Back to top of this page ]
This is a trailing or climbing annual vine that makes quick ground cover or shade. It produces a large amount of fresh green leaves that are used as a potherb as well as edible fruits, seeds, and flowers. Adapted to hot humid tropics with heavy rainfall, it prefers soils with high organic matter content and will thrive in old compost piles.
Native to west Africa, fluted pumpkin or fluted gourd is a climbing perennial that produces leafy shoots about 15 inches (50 cm) long for use at home or selling in local markets. New shoots can be harvested every three to four weeks.
Ivy gourd is another perennial climber whose leaves are eaten raw, boiled or fried in much of southern Asia. It produces a cucumber-like fruit that is pickled or eaten raw. A wild relative is considered an invasive pest in Hawaii and other parts of the south Pacific. A sterile variety that is propagated from cuttings avoids this problem.
A very fast growing annual that produces long snake-like gourds throughout southeast Asia. The immature fruit as well as the leaves are eaten, though both have a disagreeable odor until they are cooked. A substance from the roots of snake gourd is being investigated for use in limiting growth of HIV, the virus that can lead to AIDS.
Bottle gourds are the only crop known to have been cultivated in both the Old and New World before Columbus. This is likely due to the fact that the mature gourds can float and protect the seeds from salt water. They are fast climbing annuals that grow better on trellises or supports than running on the ground. They can tolerate drought but are sensitive to waterlogged soils. Bottle gourd leaves are eaten in India and in many countries around the Mediterranean.
Balsam pears are climbing perennials native to southeast Asia. They are often grown as annuals on trellises for the tender fruits. The young leaves are eaten as a potherb and are very rich in beta-carotene. They are usually boiled with at least one change of water to reduce bitterness.
Cabbage Family [ Back to top of this page ]
Also known as arugula or roquette, this low growing plant produces distinctive spicy flavored greens in six to eight weeks. It prefers cool nights. Young leaves add a snappy flavor to salads while older leaves are stronger flavored and are best steamed or stir fried.
Turnips are an important root crop throughout the world's temperate zones. The young leaves are eaten raw in salads or more commonly as a cooked potherb. Like other members of the cabbage family, turnip greens are a very nutritious and easily produced food. Some varieties have been selected that produce abundant foliage at the expense of the root crop. The flowering stems of one variety are called broccoli raab or rapini and are a specialty food in many European markets.
The most salt tolerant and one of the most heat tolerant members of the cabbage family, carinata produces a large volume of mild flavored greens very quickly. They can be eaten as a salad green when very young or as a potherb later on. Texas A & M University has introduced an improved variety called Tex-Sel.
Watercress prefers growing in constantly moving clear water, such as spring creeks. It has a sharp crisp flavor that is generally used raw in garnishes and salads. It is rich in iron and beta carotene especially given that the leaves are about 93% water by weight. Because it is often eaten raw, it is critical that the water it is grown in not be contaminated with pathogens.
Spinach Family [ Back to top of this page ]
The young tops of beetroot plants make a flavorful potherb or salad green when very young. They have quite a bit of both oxalic acid and nitrates, so should be eaten in moderation. Sugar beets are a variety of the same plant bred for its high sugar content. They are extremely salt tolerant and can be used as a salt accumulator. A good crop of sugar beets can remove about 100 kg of sodium per hectare from saline land leaving the ground less salty for future crops.
A very common garden weed in much of the world's temperate zones, lambsquarters is a very good spinach substitute when young. It is very rich in vitamin C, but the high oxalic acid content renders the calcium and iron in lambsquarters more difficult to utilize in the body.
Orach is a very drought and salt tolerant plant that produce leaves very similar to spinach in flavor, but with less oxalic acid. It is also able to produce tender foliage at temperatures warm enough to cause spinach to bolt or go prematurely to seed.
Quinoa is an important high protein pseudo- grain from the Andes in South America. The leaves are very similar to lambsquarters and make a very good potherb when young.
Hibiscus Family [ Back to top of this page ]
Native to west Africa, Roselle is famous for the bright red flower buds that are used to color and flavor Red Zinger tea and a wide variety of drinks, sauces and jellies in much of the tropics. The leaves are somewhat sour (from a high citric acid content) and mucilaginous and are served raw in salads and in curries. Leaves are harvested long before the flowers appear.
This is a perennial shrub grown in Indonesia and much of the South Pacific region. It produces up to 60 tons of leaves per hectare using a multiple harvest system. The leaves are tender and sweet and can be served raw or steamed. They must be eaten the day of harvest because the leaves wilt very quickly.
Okra is an annual native to Africa and India. Its mucilaginous seedpods are fried or used to thicken soups and stews. This is a true multipurpose plant with edible leaves, flowers, seedpods and mature seeds. It is very heat tolerant and relatively free from pests. The somewhat acid leaves are eaten as potherbs in parts of Asia and Africa. Sometimes the leaves are dried for later use. By carefully picking lower leaves it is possible to get a good crop of leaves and of seedpods from the same plants.
Leaves from other plant families [ Back to top of this page ]
The young leaves and shoots of this west African climbing perennial plant are eaten as potherbs. It is one of very few shade tolerant plants to produce good edible greens, and as such may have potential for expanded use.
Dandelion is a perennial and persistent lawn weed in much of the northern hemisphere. Traditionally it has been harvested before flowering and eaten as an early spring green. Commercial varieties have been bred that are far leafier and far less bitter. Dandelion greens are very rich in beta-carotene and vitamin C and are sold in some European and American specialty markets.
Especially popular as a gourmet potherb in Indonesia, katuk is grown throughout much of southeast Asia. It is a woody shrub that can be grown as a hedge. Leaves are 7% protein and very high in beta-carotene, vitamin C, calcium, iron and magnesium. It is a member of the Euphorbia family (along with Cassava and Chaya) and tolerates heavy rain and some flooding. It should not be eaten in very large quantities as some questions remain concerning possible toxins.
Native to Africa, Jew's mallow is sold in many markets as bunches of uprooted young plants. It is usually boiled separately and added to stews and soups later to make them thicker and more mucilaginous. It is usually planted 3 rows on a meter-wide raised bed. Leaf harvest begins in 5-7 weeks. High temperatures and soil moisture are more critical to good yield than fertilizer. In Africa, yields of 5 to 8 tons of greens per hectare are typical.
Edible leaves are produced by the Baobab trees of east Africa during the long scorching dry season because this amazing tree can store as much as 25,000 gallons (95,000 liters) of water in its trunk sometimes reaching a circumferences of 90 feet (27.5 m). These are very important to the people because of the lack of other fresh vegetable food during the long dry season. The leaves are sometimes dried and used later to thicken soups.
This is a Mediterranean annual that produces the spice coriander as a seed and the herb cilantro as a leaf. It is related to parsley and is an important flavoring in many Mexican, Indian, and Chinese recipes. It prefers clear skies and cool weather and will tolerate light frosts.
This plant is an low growing annual from tropical America. It thrives in partial shade and high soil moisture. The leaves are often eaten raw, as it is easy to overcook waterleaf and create a slimy mess. It is a close relative of purslane and like purslane, its high oxalic acid content gives it a tangy flavor.
This member of the amaranth family is an important vegetable crop in much of Africa. It grows quickly with little preparation and has beautiful flowers. Quail grass turns cooking water almost black, which might be due to tannins. It also contains quite a bit of oxalic acid.
This strongly scented annual is native to the Mediterranean but mostly used in Chinese cooking. It is a cool weather crop and hot days lead to overly strong flavored leaves. The flower heads can be eaten as well as the leaves. Both are improved by blanching or steaming.
This relative of sweet potatoes and morning glories grows either in constantly moist soil or in flooded fields. It is most popualr in southeast Asia and can't tolerate cold weather. Normally 3 cuttings are made with an interval of about 5 weeks between each one. Impressive yields up to 90 tons per hectare are possible. Kangkong is sometimes eaten raw in salads but more commonly as a vitamin rich potherb.
As the name implies this plant is native to New Zealand and can be used as a substitute for spinach. It is a low growing plant that, unlike spinach, thrives in hot weather. It responds to leaf harvest by putting out new lateral branches, thus making it an excellent "cut and come again" greens crop. Harvesting usually begins about six weeks after planting. Young leaves are added raw to salad and older ones are boiled or stir fried. New Zealand spinach contains relatively high levels of oxalic acid which makes its calcium difficult to absorb.
A relatively common weed in gardens and along stream banks in the northern temperate zones, nettles is considered to be an indicator of rich fertile soil. It gets it name from the irritation or sting that people experience when brushing their skin against nettles leaves. This irritating quality is quickly lost when the leaves are either cooked or dried. Nettles makes extremely nutritious greens. They are sometimes steamed, then puréed and added to rice. Juice from raw nettles leaves contains a proteolytic enzyme that is sometimes used as a coagulant, like rennet, in making cheese. Dried nettle leaf tea is used in herbal medicine. It is also useful in treating fungal infection in plants.
Basella is another excellent hot weather tolerant spinach substitute. It is an enthusiastic climber and is often grown on fences or up into trees. The flavor and texture of the leaves is better when the plant is grown in partial shade. It is very sensitive to cold weather. Repeated leaf harvests can begin about 8 weeks after planting. It is an annual in the temperate zones but perennial in the humid tropics. It is an excellent potherb and its mucilaginous quality is used to thicken soups.
The familiar iceberg type lettuce common in salads in the US doesn't grow well in the tropics. Indian lettuce is much better adapted to hot humid conditions. It grows up to six feet (two meters) high and is a very productive crop. The leaves are somewhat more nutritious than temperate lettuces, but also tend to be somewhat more bitter. In addition to use of young leaves in salads, Indian lettuce is sometimes cooked as a potherb.
This is an annual herb that is a common garden weed throughout much of the world's tropical and sub-tropical zones. Leaves of this plant are sometimes eaten raw when very young, but more often steamed. They are dried for later use in parts of Africa and in the Philippines. In Zimbabwe they are lightly boiled with a little peanut butter mixed in afterwards.
This plant is a small tree with a hard, useful wood that is a native of India. The leaves are often fried quickly until crisp then ground or crumbled into curries and other dishes throughout Southeast Asia. They have a strong flavor and aroma, somewhat like anise, that persists even when the leaves are dried and used much later. The roots and bark as well as the leaves are also used both externally and internally in herbal medicine.