A large multi-stemmed shrub or small to medium-sized evergreen tree, 4-5 m up to 10 m high. Main stem erect with rigid branching. Bark pale grey.

Spines at each node, in pairs at right angles to the stem, straight, woody, up to 25 mm long. Leaves in clusters on dwarf side shoots below spines, or opposite on young stems, small, 15–50 × 7–25 mm, but usually 30–50 × 15–25 mm, softly hairy when young, becoming hairless, olive-green, paler green below, 2–5 pairs of lateral veins, with small domatia; apex broadly tapering, base tapering; petiole 1–2 mm long; stipules triangular with long point, falling early.

Flowers greenish white, scented, about 5 mm in diameter, inconspicuous, in short branched heads, 10–20 mm in diameter, on dwarf spur-branchlets, from midwinter to midsummer (July–December).

Fruit ovoid, about 13 × 10 mm, blue-black, sometimes 1-lobed and asymmetric, or shallowly 2-lobed, bluish grey when ripe, edible and pleasantly flavoured; 1–2 seeds in spring and summer (September–January).