Agroforestree Database

Local names:
 Afrikaans (enkeldoring-noemnoem), Amharic (agam), Arabic (emir), English (simple-spined carissa,simple spined num-num,Arabian num-num), Luganda (muyonza), Swahili (mtanda-mboo), Tigrigna (agam)

Carissa edulis is a spiny, much branched, small tree, shrub or scrambler, up to 5 m in height, with a milky sap. Bark grey, smooth, young branchlets with or without hairs; spines simple, straight, 2-5 cm long, usually single. 

Leaves ovate to ovate-elliptic, opposite, occasionally almost circular, 2.5-6 x 1.8-3 cm, leathery, dark green above, paler green below, with or without short, soft hairs; lateral veins obscure; apex tapering, often with a bristlelike tip; base rounded to shallowly lobed; margin entire; petiole 1-4 mm long.

Flowers white tinged with purple, red or pink, up to 1.8 cm long, about 2 cm in diameter, slender, tubular, with corolla lobes overlapping to the right, sweetly scented, in terminal heads about 4 cm in diameter.

Fruits ovoid to almost spherical, up to 1.1 cm in diameter, red-black, ripening to purplish black, containing 2-4 flat seeds. 

C. edulis closely resembles C. bispinosa, the obvious feature separating them being that C. edulis has straight thorns and those of C. bispinosa are Y-shaped. The name Carissa is probably derived from the Sanskrit ‘corissa’, a name for one of the Indian species of the genus. The specific name, edulis, means edible.

Ecology

C. edulis is found in Arabia and reaches through tropical Africa to the Transvaal, Botswana and north and northeast Namibia, in warm bushveld and scrub. In the Transvaal it occurs in the lowveld of the north and northwest. In Uganda it is usually found on termite mounds in wooded grassland, especially in low-lying areas associated with Grewia similis and also in thickets in woodlands, forest edges and secondary scrub. It prefers dryish conditions. It is a tree of deciduous forest and coastal thickets, extending across the region from Senegal to Cameroon and throughout the drier parts of tropical Africa and across Asia to Indo-China. It has been reported as a parasite of henna plants in northern Nigeria.

Native range
Botswana, Cambodia, Cameroon, Eritrea, Ethiopia, Ghana, Guinea, Japan, Kenya, Myanmar, Namibia, Nigeria, Saudi Arabia, Senegal, South Africa, Sudan, Tanzania, Thailand, Uganda, Vietnam, Yemen, Republic of

Tree management

The slow-growing trees respond well to pruning.

Seeds storage behaviour is orthodox, and their viability can be maintained for more than 12 months in dry air storage at 5 deg. C. There are about 28 000-30 000 seeds/kg.

C. edulis is found in Arabia and reaches through tropical Africa to the Transvaal, Botswana and north and northeast Namibia, in warm bushveld and scrub. In the Transvaal it occurs in the lowveld of the north and northwest. In Uganda it is usually found on termite mounds in wooded grassland, especially in low-lying areas associated with Grewia similis and also in thickets in woodlands, forest edges and secondary scrub. It prefers dryish conditions. It is a tree of deciduous forest and coastal thickets, extending across the region from Senegal to Cameroon and throughout the drier parts of tropical Africa and across Asia to Indo-China. It has been reported as a parasite of henna plants in northern Nigeria.

Although trees are difficult to establish, they can be grown from seed. Presowing treatment is not necessary, and germination of fresh seed is good. Artificial regeneration using seedlings and wildings is also possible.

Poison:  In Kenya, a piece of the root is fixed into a hut roof as a snake repellent.

  Fruits are sweet and pleasant to eat; in Ghana, they are normally added to the food of invalids as an appetizer. Vinegar can be made from them by fermentation; in Sudan and Kenya, they are made into a jam. The roots are put into water gourds to impart an agreeable taste and are added to soups and stews for the same reason.

Goats and camels in the dry parts of Sudan browse on C. edulis.

The species is a source of excellent firewood.

Medicine:  Roots contain an active ingredient, carissin, that may prove useful in the treatment of cancer. The twigs contain quebrachytol and cardioglycosides that are useful as an anthelmintic against tapeworm. In Guinea, the boiled leaves are applied as poultice to relieve toothache. Root bark is mixed with spices and used as an enema for lumbago and other pains in Ghana; root scrapings are used for glandular inflammation; ground-up roots are used as a remedy for venereal diseases, to restore virility, to treat gastric ulcers, cause abortion, and as an expectorant. An infusion of roots along with other medicinal plants is used for treating chest pains, and a root decoction is also used for treating malaria.

Ornamental:  C. edulis is an attractive tree that is suitable for planting in amenity areas.

The abundant branching habit and the presence of spines make the plant suitable for planting as a protective hedge.