Acacia lahai Benth.

Acacia lahai is a flat-topped tree 3-15 m tall with rough brown or grey-brown bark. Young branchlets brown to blackish-purple, pubescent. Stipules spinescent, up to 7 cm long, straight, subulate but not enlarged or fusiform, prickles absent below stipules. Bark gray-brown and fibrous in texture. Leaves pinnate, pinnae 3-15 pairs, leaflets glabrous 10-28 pairs, 1.5-4.5 mm long 0.3-1.0 mm wide. Flowers cream or white, sessile, in spikes 2.5-7 cm long on peduncles 0.7-2 cm long, axis with many subsessile or subsessile glands. Calyx 0.5-1.25 mm long. Corolla 2-3 mm long, glabrous, 4-5 lobed. Stamen filaments 4.5-5 mm long; anthers 0.1 mm across with a caducous gland. Fruit a brown, straight or falcate, dehiscent pod, glabrous on stipe, 4-7 cm long x 1.5-3 cm wide. Seeds obliquely obovate, flattened, 6-7 mm long x 5 mm wide. The generic name ‘acacia’ comes from the Greek word ‘akis’, meaning point or barb.

A. lahai is a hermaphroditic species.

A. lahai is characteristic of high altitude woodland and wooded savanna. Locally common where upland forest has disappeared it forms dense woodlands invading grasslands.

The tree is commonly left as tree shade in pastures.

Propagation by seed is the most preferred method.

A. lahai is a fast growing tree commonly managed by lopping.

Insect pests cause seed damage.

Seed storage behaviour is orthodox, there are approximately 4 000 seeds/kg. The damaged, lighter seeds can be selectively collected by immersing in water. Pre-sowing treatment not necessary.

Erosion control: An important erosion control tree in wooded grasslands and savanna. Shade or shelter: The tree's broad canopy and heavy foliage make it a good shade tree. Nitrogen fixing: The tree is nitrogen fixing thus improves soil fertility. Boundary or barrier or support: Dry timber used as fence posts.

Fuel: The tree is a significant source of firewood, and makes excellent charcoal. Timber: Wood red, hard and durable. Timber is used for construction in Kenya. Gum or resin: An edible gum is collected from A. lahai. Tannin or dyestuff: Aqueous bark extracts are sprinkled on pottery to impart a reddish finish. Medicine: Bark used for the treatment of skin eruptions in children, clearing toxicaemia of pregnancy and bowels and also as an astringent.