Balanites aegyptiaca (L.) Del.

Zygophyllaceae
(Often placed either in the Simarubaceae or Agialidaceae family)

Description

Tree or shrub reaching a height of up to 10-12 m, with a furrowed stem up to 45 cm in diameter, with a yellowish-grey to dark brown bark, divided into thick scales by vertical cracks, which reveal the younger yellowish bark beneath. More or less spherical canopy, in one or several distinct masses, yellowish-green in colour. Main branches usually erect with sudden curves, very intricate and dividing in a great number of greenish branchlets having a weeping habit. Vertical green suckers are very common around the base of the stem, whenever they are not browsed by livestock. Shoots have strong green spines reaching 8-9 cm in length, usually alternate and opposite to the petioles of the leaves (liable to puncture care tires). Leaves are bi-foliolate (which is a characteristic of the genus), on a 1.0-1.5 cm long petiole; folioles obovate, more or less lozenge-shaped, 1-6 cm long (exceptionally 7.5 cm), and 0.5-4 cm wide (exceptionally 6.5 cm), sub-sessile or on petiolules of 0.5-1 cm of length, pubescent underneath in young leaves, rather glabrous in the adult. Green-yellow flowers a little over 1 cm in diameter, solitary or fasciculate in groups of five flowers, cymes born at the base of leaves or spines. Flowers of the type 5S + 5P + 10E on a small disc, ovary tomentose. Flowering buds are tomentose, ovoid. The fruit is an ellipsoid drupe 3-4 cm long, at first green and tomentose, then yellow and glabrous when mature, but rarely found at that latter stage in the bush, as it is usually consumed before reaching maturity. The fruit skin is thin and sometimes wrinkled. The stone is extremely hard, brown, ellipsoid. The pulp surrounding the stone is greenish, then yellowish when ripe. When the fruit is ripe, the skin becomes “parched” and can be easily separated from the pulp and the pulp is sweetish and edible. The wood is light yellow-brown, slightly glossy, compact and with a rather fine structure.

Distribution

This species is to be found in all the dry lands of Africa down to Katanga and Tanzania in the south. It is common in Israel, Jordan, the Arabian Peninsula, and the drier parts of Pakistan and India. In the Sahel, flowers appear long before the rainy season (April) and fruits ripen and fall in December-January. Foliage does not, as a rule, fall all at the same time. Mostly found on heavy soils around ponds, along wadis, in occasionally flooded depressions and the fossil quaternary valleys of the Sahara; on rocky-clayey screes; also on sandy soils, but then always where there is a deep layer of fine material. It is found up to 2 000 m above sea level. The species is very tolerant to drought and thrives under rainfalls of 200 mm, or even less, where there is additional water supply (e.g. Banks of the Nile in the Sudan). It spreads from the margin of the dessert to the woody savannahs with 900 mm of annual rainfall.

Propagation

A rather lengthy soaking of the fruit in water is needed to remove the pulp from the fruit. The seed or kernel thus extracted must be sun-dried before storing. The species is rather adaptable as a rule and the production of young shoots for browsing is sometimes induced by a slight trimming towards the end of the dry season.

Products and uses

The wood is durable and resistant to insect damage. It is easy to saw, split, polish, and turn. It is used for making tool-handles, parts of donkey or camel saddles, small furniture – stools, low tables – candlesticks, etc. The green leaves are sought after by sheep, goats and cattle, but they are especially relished by camels. Seasonal defoliation is more or less pronounced, depending on regions or maybe on certain populations or strains. Shed, dried-up leaves are still sought after by camels and sheep. However, it is the green shoots which are most relished, either young shoots or the leaves which normally appear in June-July in the Sahel, or young suckers from the bottom of the stem. Camels may browse on this species up to 18-19 hours a day, taking 340-360 bites and ingesting 1 700 to 1 800 gr of green matter with a water content of 969 L, 026 gr. It is appreciated by all livestock. Sheep and goats spit out the stones, but cattle swallow them several times during rumination, and camels swallow them after crushing with their teeth. This seed is rich in protein (27%) and contains an oil (41%) called “Zachun oil” which probably entered into the composition of the scriptural “Nard”. This oil is edible and its extraction leaves a meal whose feeding value is slightly below groundnut meal. Fruits are sought after by elephants, baboons, and black-backed jackals. Roan antelopes consume the pulp, but reject the stones. The aqueous emulsion from the fruit is lethal to the water-fly Cyclops, a vector of the Guinea-worm, and also to the Aquatic Molluscae, vectors of bilharzia, as well as for two larval stages of the parasite responsible for this disease. This emulsion is also used for killing fish; such fish may be consumed by man as well as water treated with this preparation. The same properties, due to the presence of a saponoside, are attributed to the bark. The kernels have been reported to help cure some intestinal diseases. A tar is also extracted from the seed which is said to be efficient against camel’s gall. Boiled flowers, called “dobagara” are consumed with Couscous. The stones called “Kwai Kwaye” are used as pawns in various games. A large number of medical uses have also been reported.

Main References

Baumer, M. 1983. Notes on Trees and Shrubs in Arid and Semi-arid Regions. FAO/UNEP programme “Ecological Management of Arid and Semi-Arid Rangelands in Africa, Near and Middle East” (EMASAR Phase II). 270p.