Agroforestree Database

Local names:
 Afrikaans (sekelbos), Amharic (ader,ergett-dimmo), Arabic (hurgam,kaddad,kadada,hurgan,heghem,hegam,um Kedad,kadad), Bemba (kansalonsalo,katenge), English (sickle bush,marabou thorn,Chinese lantern tree,kalahari Christmas tree,bell mimosa), French (mimos

Dichrostachys cinerea is a semi-deciduous to deciduous tree up to 7 m tall with an open crown. Bark on young branches green and hairy but dark grey-brown and longitudinally fissured on older branches and stems; smooth on spines formed from modified side shoots. Slash cream coloured to light yellow. Strong alternate thorns, up to 8 cm long, almost at right angles, slightly recurved, grow out of the branches and may bear leaves at the base. Twigs grey brown violet, with prominent light lenticels.

Leaves bipinnate; rachis 4-8 cm, with 5-15 (max. 19) pairs of pinnae, which each bear (min. 9) 12-22 (max. 41) pairs of leaflets; terminal pair of pinnae shorter, dark green, underside pale. Leaflets about 8 x 2.5 mm wide; leaflets and petioles very tomentose and ciliate. 

Flowers very characteristic in bicoloured cylindrical, dense, petioled, pendulous spikes (bottlebrush), 6-8 cm long and fragrant. Terminal lower flowers hermaphroditic, with 1 pistil and 10 yellow stamens each. Upper flowers of a hanging spike are sterile, reddish or pale purple, with protruding staminodes.

Pods narrow, yellow or brown; generally twisted or spiralled, up to 100 x 15 mm, in dense, stalked, intertwined clusters; indehiscent. About 4 black seeds with a spot at one end per pod.

It seems possible that 2 subspecies can be recognized: D. cinerea. ssp. africana and D. cinerea ssp. nyassana . The latter tends to grow larger and has larger and less hairy leaves and leaflets.

The generic name ‘Dichrostachys’ means ‘2-coloured spike’, and ‘cinerea’ refers to the greyish hairs of the typical subspecies, which is confined to India; from the Greek ‘konis’ and the Latin ‘cineres’. In South Africa it is called the ‘Kalahari Christmas tree’, and because of the attractive 2-coloured hanging flowers some people call it ‘tassels for the chief’s hat’. But most commonly it is known as the ‘sickle bush’, because the young pods are curved like sickles.

Ecology

D. cinerea penetrates clear-cut areas far into the rainforest zone. In Malaysia, it occurs in areas with strong seasonal climate, usually on poor, occasionally clayey soils, in brushwood, thickets, hedges, teak forest and grassland. Forms dense hammocks on lateritic soils in Senegal and Sudan, while in India it occurs in dry deciduous forest. It can be an indicator of overgrazing in low rainfall areas. Usually not frost resistant and tolerance is less on poor soils, but definitely drought resistant. It is fire resistant and does not tolerate waterlogging.  It is a weedy species. For instance in Cuba, the tree is unchecked and forms veritable forests on hill land or in areas on which cane growing has been discontinued. In some parts of central Cuba, there are reports that whole farms have been rendered useless by this foreign weed.

Native range
Cameroon, Djibouti, Eritrea, Ethiopia, Ghana, Kenya, Madagascar, Malawi, Nigeria, Somalia, South Africa, Sudan, Swaziland, Tanzania, Togo, Uganda, Zambia

Tree management

It grows at a medium to slow rate, 6-8 cm/year. For fuelwood plantations, dune stabilization, ravine afforestation, or erosion control, the spacing should be 3 x 5 m; for silvopasture, 8 x 8 m. Dense plantings help stabilize gully plugs and check-dams. To get maximum fuel biomass, the plants should be harvested at 10 years. However, if the production objective is only fodder, trees should be coppiced every other year after reaching about 5-6 m in height. The plant has moderately vigorous coppicing ability and can also be pollarded and lopped. A plant in the range of 7-8.5 cm collar diameter is suitable for coppicing, and the whole plant can be harvested 15 cm above ground level. The number of regenerated shoots varies between 5 and 9, of which 2-3 branches attain better growth in height, diameter and biomass.

For soil conservation, the species should not be disturbed in any way. Its prolific root suckers will then provide natural spread for complete ground cover within a few years. Later a fodder harvest can be taken by lopping leaves and pods. In the 6th year, the total aboveground biomass is about 31 kg (dry). Thus an average yield of 3.4 t (1.2 t dry) fodder and 22.8 t (11.1 t dry) firewood may be expected on the 6th year from 1 ha of wasteland. It yields about 1 kg of seed pods/tree.

D. cinerea enroaches rapidly on overgrazed, trampled ground and on old lands where the grass cover has been removed. It is difficult to eradicate as it shoots again from portions of root. In certain situations, mechanical or chemical control measures are the only ways to control the potentially serious weed.

Orthodox seed storage behaviour; little loss in viability during 26 years of hermetic storage at room temperature. Add ash to stored seed to reduce insect damage. Can be stored for up to 10 years at room temperature if kept dry and free from insects. There are 50 500-66 500 seeds/kg.

D. cinerea penetrates clear-cut areas far into the rainforest zone. In Malaysia, it occurs in areas with strong seasonal climate, usually on poor, occasionally clayey soils, in brushwood, thickets, hedges, teak forest and grassland. Forms dense hammocks on lateritic soils in Senegal and Sudan, while in India it occurs in dry deciduous forest. It can be an indicator of overgrazing in low rainfall areas. Usually not frost resistant and tolerance is less on poor soils, but definitely drought resistant. It is fire resistant and does not tolerate waterlogging.  It is a weedy species. For instance in Cuba, the tree is unchecked and forms veritable forests on hill land or in areas on which cane growing has been discontinued. In some parts of central Cuba, there are reports that whole farms have been rendered useless by this foreign weed.

Natural regeneration is strongest by root suckers. Within a period of 10 years, an individual of this species can produce 130 new stems in a radius of 15 m by its root suckers. Artificial propagation by transplanting root suckers or by using root cuttings is likewise the easiest and usually most successful method of propagation.

Direct sowing of seed is also possible. The freshly collected ripe seeds take long to germinate (15-20 days), mainly due to a thick seed coat. Scarified seeds give better germination, and a pretreatment of 25 minutes in concentrated sulphuric acid gives optimum germination of 3-7 days for freshly collected seeds. Three-year-old seeds require only a 15-minute pretreatment for optimum germination. Under controlled conditions, more than 75% germination may be expected. As soon as the pods ripen on the tree, they should be collected and the seeds taken out, dried and stored. This way, a reasonable amount of seeds could be saved from insect attack. About 1 million seeds/year are expected from a plant and most of the seeds are viable.

Owing to its strong capacity for natural regeneration, it has high potential for ravine afforestation and other soil conservation purposes on difficult sites.

Erosion control:  The plant is widely used for sand dune stabilization and soil conservation; in India, it is recommended for shallow soils, arid western and subhumid alluvial plains and highly degraded calcareous wastelands.

  Fruit and seeds from D. cinerea are edible.

Cattle, camels and game (giraffe, buffalo, kudu, Lichtenstein’s hartebeest, nyala, impala, klipspringer, red duiker and Damara dik-dik) relish the juicy pods that drop to the ground and even eat the young twigs and leaves. Leaves are highly palatable, rich in protein (11-15% crude protein) and mineral content. Young shoots and pods are also browsed by smaller domestic animals. Pods and seeds do not contain hydrocyanic acid, minimizing the chance of poisoning animals.

Apiculture:  The flowers are a valuable honey source.

The wood is dense, burns slowly with few sparks and emits a non-toxic smoke, making it excellent firewood. It often grows many small trunks, ideal in size for carrying in a headload.

Fibre:  The bark yields a strong fibre used for various applications such as twine. The debarked roots are used for strong plaiting work such as for racks and baskets.

Timber: D. cinerea yields a medium to heavy, durable hardwood with a density of 600-1190 kg/cubic m at 15% mc. Heartwood red or dark purple with darker streaks, sharply differentiated from the yellowish-brown sapwood; grain straight or slightly interlocked; texture rather fine and even. Due to its generally small dimensions, its utilization is limited making such items as walking sticks, handles, spears and tool handles. Fencing posts are durable and termite resistant, easily lasting up to 50 years.

Medicine: The bark is used to treat dysentery, headaches, toothaches, elephantiasis and acts as a vermifuge. Root infusions are taken for leprosy, syphilis coughs, as an anthelmintic, purgative and strong diuretic. Pounded roots and leaves are used to treat epilepsy. The roots are chewed and placed on the sites of snakebites and scorpion stings, and the leaves, which are believed to produce a local anaesthesia, are used for the same purpose and also as a remedy for sore eyes and toothache. Leaves are taken as a diuretic and laxative, and used for gonorrhoea and boils; powder from leaves is used in the massage of fractures. The plant is used as a veterinary medicine in India.

Nitrogen fixing: D. cinerea fixes atmospheric nitrogen.

Ornamental:  The sickle bush can be planted in the garden to show off the beautiful pink and yellow lantern flowers during early summer and the interesting branching pattern during winter. A favourite plant to train as a bonsai.

Thorn branch enclosures prevent livestock from straying at night and protect vegetable gardens, cash crops and fodder- or thatch-grass reserves from livestock. Since it is difficult to control, having an aggressive weedy c

Soil improver:  The leaves, rich in nutrients, are frequently used as a green manure. In the Sahel, particularly along riverbanks, it is said to improve soils.

Intercropping:  Highly compatible with certain improved arid-zone grass and forage species such as Cenchrus ciliaris, Lasiurus sindicus and Stylosanthes hamata, making it well suited to silvoipastoral systems.