It occurs widely in coastal, montane or riparian forests of southern Tanzania,^[1] Mozambique, Eswatini and eastern South Africa. In South Africa it is present in the Eastern Cape, KwaZulu-Natal, Mpumalanga and Limpopo provinces.^[4] The Hluhluwe River is named after this species,^[7] due to its prevalence on the banks of the river. The species is virtually confined to White’s Tongaland-Pondoland centre of endemism.^[1]

Their thick (up to 15 cm) and 10 to 30 m long ropes^[2] have sturdy, sideways-directed spines which may grow in clusters, and encircle the stems. The spines which are up to 10 cm long,^[8] hook onto adjacent vegetation to direct the plant towards the canopy. The bark is dark greyish brown.

The alternate leaves are up to 8 cm long, finely compound and are bluish green on their upper surfaces.^[2] The 21 to 41^[8] oblong leaflets (i.e. 10 to 20 pairs plus terminal) have a sub-opposite or alternate arrangement.^[9] The leaflets close in overcast weather, and the foliage is popular with browsing animals.

Their very small,^[9] sweetly scented flowers are creamy-white in colour.^[2] They appear in early summer, and are born in dense terminal or axillary clusters.^[9] The small and thin seed pods measure about 5 by 2 cm. They are papery in texture^[3] and lemon-yellow to pale brown in colour.^[2] The indehiscent fruit which hold 1 to 3 seeds each,^[1] are often produced in profusion. They appear in clusters on horizontal branch tips, from late summer.^[3][2]

The Zebra-wood is also armed and has an overlapping range, but its leaflets are fewer (7 to 13) and larger, while its flowers vary from white to pink.^[4] Other Dalbergia species of the region have hairy pods, or velvety undersides to the leaflets. The Thorny elm has simple leaves.