A shrub or small to medium sized tree from the Salicaceae family that can grow to as tall as 15 m. It is a hardy, evergreen or semi-deciduous tree, with grey to brown bark; semi-deciduous because the old leaves drop off during flowering but almost immediately after the old leaves are shed, new leaves will grow. Dovyalis longispina is known for its conspicuous, slender, straight spines, up to 80 mm long, borne along its branches. The spines and the twigs are covered with small warts.

The crown is noticeable, with its glossy, dark-green, roundish leaves. New leaves of the Coast Kei-apple appear reddish. The leaves are usually alternate, oval, egg-shaped to top-shaped, tips bluntly pointed, rounded or notched, with untoothed margins.

With male and female flowers on separate trees, that means only female trees can bear fruits. Both male and female flowers are small, whitish-yellow, in clusters in the axils of the leaves and appear in spring, from August to October. Male flowers are in larger clusters of up to 10 flowers, female flowers are solitary or in groups of 2 or 3. The images captured by Geoff Nichols clearly show the difference between the male and female flowers.

Female trees bear oblong fruits, 15 mm in diam., smooth, fleshy, bright red with white spots when mature, with an enlarged and persistent calyx. This edible fruit tastes slightly acidic with a touch of sweetness. Each fruit holds up to 2 woolly seeds, 9 mm long.

Dovyalis longispina can be separated from Dovyalis caffra, another closely related species, by its narrower and often more pear-shaped leaves, which are most often alternate. Dovyalis longispina can be distinguished from Dovyalis zeyheri by its conspicuously warted spines, leaf veins that are not raised below and its fruits that are spotted with white.