For the identification of insects and other fauna and flora of South Africa.

Wednesday, January 20, 2016

Small-leaved Sickle Bush (Dichrostachys cinerea africana)

Family Fabaceae
Dichrostachys cinerea is a spiny, deciduous shrub or small tree, up to 7 m high, with a rounded crown, 3 m wide. The bark is rough, yellow to grey-brown and frequently fissured and the stem is rarely thicker than 230 mm. The twice-compound, petiolate leaves are very variable in size with 4 to 19 pairs of pinnae and each pinna with 9 to 41 pairs of leaflets, giving it an Acacia-like appearance. The petioles (leaf stalks) are up to 50 mm long and the leaf length varies between 10 and 160 mm. The young twigs are slightly hairy and a characteristic feature is that the spines are not modified stipules but hardened branchlets, ending in a straight, sharp point.
The flowers are 25 to 50 mm long, pendulous spikes that are borne in the leaf axils, singly or in bundles. The pleasant-smelling fluffy flowers are lilac in the upper half and yellow in the lower, giving rise to the descriptive name Chinese lantern tree in other countries. Its flowering season is spring, generally from September to February.
Each flower produces a mass of flat, coiled green pods that turn brown and later fall to the ground. Each pod contains a large number of seeds; young pods are curved, resembling sickles.
EcologyDichrostachys cinerea is a nitrogen-fixing legume and therefore has a positive effect on the nitrogen content of the soil. It has the ability to colonize disturbed veld quickly and curbs erosion. The pods are very nutritious to animals and are eaten by stock and game, including monkeys, rhinoceros and bushpigs.
It sometimes forms impenetrable thickets and becomes a problem plant for veld managers. It was introduced to the West Indies during the 19th century, where it has invaded range lands and caused significant economic losses in agricultural production. It is important that propagules of this species do not reach areas of similar climates, such as Hawaii or South America, where risk assessments have indicated a high chance of invasiveness.
Uses and cultural aspectsDichrostachys cinerea makes impressive bonsai specimens. The hard and durable wood is also termite resistant, making it ideal for fence posts. It is also used to make tool handles, milk pots, smoking jars, and fibre from the bark. It is often planted to serve as live fencing and as a fodder. The roots are used as a local anaesthetic for ailments such as snake bites, scorpion stings and toothache. In Botswana, parts of the tree are used as a tapeworm cure. It also makes high quality firewood.