Vachellia permixta

Vachellia permixta, the slender thorn and in Afrikaans the slapdoring (slack or lax thorn), is a spiny, pod-bearing shrub or small tree reaching heights up to 4 m (SA Tree List No. 179.1). The specific name, permixta, is Latin meaning confused, referring to the tree’s strong resemblance to V. nebrownii, V. exuvialis and V. swazica. 

The bark is reddish brown and peeling from longitudinal fissuring and transversal splitting. The tree is sometimes multi-stemmed, while the lower part of a main stem may be up to 4 cm in diameter. Young stems are grey-haired, sometimes rust-coloured near stem-tips.

The stipules of V. permixta are paired spines, up to 6 cm long. Usually straight, the white spines or thorns may curve back slightly. They are hairy when young.

The compound leaves grow in fascicles of up to eight leaves on hard cushions between the spines. Each leaf consists of up to five pairs of pinnae, each pinna has four to ten pairs of pinnules or leaflets. The oblong leaflets with acutely pointed tips are 2 mm to 6 mm long, 1 mm to 2 mm wide and notably hair-fringed. There are glands on the rachis and sometimes on the leaflet margins.

One or two flowerheads grow per node, appearing on new growth. The hairy-stalked flowerheads are spherical and yellow from the numerous stamens, much longer than sepals and petals, as is common in Vachellia. Flowering happens early in summer.

The small, sickle-shaped pod is brown when ripe, covered in reddish glands. The pod is up to 5 cm long and 1 cm wide. The seed is olive to brown, about 3,5 mm in diameter.

The species distribution is in Limpopo and North West, as well as in some neighbouring countries.

The habitat is rocky slopes and ridges in dry areas, the trees growing in shallow, gravelly soils. The species is not considered to be threatened in its habitat early in the twenty first century (Carr, 1976; Coates Palgrave, 2002; Schmidt, et al, 2002; iNaturalist; http://redlist.sanbi.org).