Agroforestree Database

Local names:
 Afrikaans (papierbasdoring,platkroonsoetdoring), Arabic (kochai,kouk,kuk,kuka), Bemba (mutandafiwa,munganunshi), English (white thorn,umbrella thorn,flat-topped thorn,paperbark thorn,paperbark acacia,Natal camelthorn), Fula (gie,daneji), Hausa (fara kaya

Acacia sieberana is a tree 3-25 m tall, 0.6-1.8 m in diameter, with a rather rounded crown; trunk 6 m high; bark rough, yellowish, flaking off in small, rectangular, grey-brown scales; slash yellowish with dark red edges, fibrous, exuding clear gum; spines in pairs at the nodes, straight, white, narrow, tapering to a sharp point, 0.6-12 cm.

Leaves usually sparsely hairy, bunched into small clusters, 6-23 (max. 35) pairs of pinnae 2.5-2 cm long, densely crowded, overlapping, with a common stalk 5-10 cm long; leaflets in 14-52 pairs, 2-6.5 x 0.5-1.5 mm, narrowly oblong, rounded at the apex, with a central midrib; stalks ending in a minute spine.

Flowers cream, white or pale yellow, in heads about 13 mm across, on a slender stalk up to 5 cm long, with a whorl of tiny bracts near the apex; heads may be solitary or in small clusters near the branchlets.

Fruit shiny brown, straight or slightly falcate, with more or less parallel margins, 1.3 cm thick, 9-21 cm long, 1.7-3.5 cm wide, glabrous or nearly so, indehiscent, splitting open tardily releasing about 12 seeds; seeds big - 1 cm long, hard, flat, embedded in a yellow-greenish pulp.

Two varieties are recognized: A. sieberiana  var. sieberiana and A. sieberiana   var. villosa. The generic name ‘acacia’ comes from the Greek word ‘akis’, meaning ‘point’ or ‘barb’. The species was named after Franz Wilhelm Sieber, a Bohemian botanist, plant collector and traveller of the early 18th century.

Ecology

A. sieberana grows in the savannah and woodland. It occurs with various botanical characteristics in the entire Sahel and other semi-arid regions in Africa. Various varieties and local races exist. The species is especially suited for riverbanks or low ground and replaces A. nilotica in the south of the latter’s natural range. A. sieberana is drought and frost resistant.

Native range
Angola, Benin, Botswana, Burkina Faso, Cameroon, Chad, Congo, Cote d'Ivoire, Eritrea, Ethiopia, Gambia, Ghana, Guinea, Kenya, Liberia, Malawi, Mali, Mauritania, Mozambique, Namibia, Niger, Nigeria, Portugal, Senegal, Sierra Leone, South Africa, Sudan, Swaziland, Tanzania, Togo, Uganda, Zambia, Zimbabwe

Tree management

The trees respond well to lopping, pollarding and coppicing. The seedlings need to be protected from fire and browsing.

The seeds can be stored if kept cool, dry and insect free; ash is added to reduce insect damage. On average there are 3250 seeds/kg.

A. sieberana grows in the savannah and woodland. It occurs with various botanical characteristics in the entire Sahel and other semi-arid regions in Africa. Various varieties and local races exist. The species is especially suited for riverbanks or low ground and replaces A. nilotica in the south of the latter’s natural range. A. sieberana is drought and frost resistant.

The trees are easily raised from seeds and are quick growing. Germination rates of 60% have been achieved for seeds boiled and soaked in water for 24 hours before sowing.

Poison:  The leaves contain large quantities of prussic acid at certain times, especially when wilted, and have been known to cause death in cattle.

  A. sieberana produces an edible gum.

Pods, young shoots and leaves are highly nutritious and serve as forage for livestock in the dry season. In Sudan, pods are collected for fattening sheep but are said to taint milk.

Apiculture:  Flowers are good bee forage, and hives are often placed on the trees.

A. sieberana is a good source of firewood and charcoal.

Fibre:  The bark is used to make a cordage fibre.

Timber:  The termite resistant, moderately hardwood has a featureless, off-white grain with little distinction between heartwood and sapwood. It is easy to work and is used in making furniture, tool handles and mortars.

Shade or shelter:  A. sieberana has occasionally been planted as hedge, a windbreak and a shade tree in villages, rangelands and fields.

Tannin or dyestuff:  The bark and pods contain tannin.

Medicine:  Pounded bark is used to relieve fever in children. A decoction of the root is taken as remedy for stomach-ache. The bark, leaves and gums are used to treat tapeworm, bilharzia, haemorrhage, orchitis, colds, diarrhoea, gonorrhoea, kidney problems, syphilis, ophthalmia, rheumatism and disorders of the circulatory system. It is also used as an astringent. The pods serve as an emollient, and the roots for stomach-ache, acne, tapeworms, urethral problems, oedema and dropsy.

Gum or resin:  The tree yields a gum of good quality that has been used to make ink.

Nitrogen fixing:  A. sieberana fixes atmospheric nitrogen.

The branches make good fences.