Ziziphus rivularis is drought-resistant and has attractive, glossy, olive-green foliage with variable venation, as well as an attractive grey stem. This is the only South African Ziziphus without thorns. Ziziphus rivularis is a fast-growing, small tree or large shrub that grows up to 7 m tall, with a spread of up to 4 m. It is an evergreen to semi-deciduous, multi-stemmed tree. The bark is smooth and whitish, becoming dark grey in colour. The leaves are glossy, lanceolate to ovate-lanceolate, with sparse hairs on younger leaves, but becoming hairless at maturity. They are simple, alternate and spirally arranged. The inconspicuous yellow flowers appear in early to midsummer, from November to January.