Shrub or tree up to 8 m high, usually spiny, with spreading or pendulous branches; young stems and spines greyish-green becoming light brown, minutely puberulous or tomentellous, glabrescent. Spines arising 0.1–0.4 cm above the leaf-axil, (0.4–)2–8(–11.5) cm long, naked except for a few scale-leaves or rarely a single short lateral spine. Scale-leaves rare, on young spines, falling quickly, c. 0.75 mm long. Foliage leaves only on the stems, puberulous to tomentellous, often glabrescent, subsessile or with up to 2(–3.5) cm long petiole; petiolule (0–)1–5(–8) mm long; leaflets narrowly elliptic to broadly ovate or obovate, 1–6.8 x 0.3–5 cm, leathery, cuneate at the base, bluntly acute to obtuse or rounded at the apex. Flowers 5-merous, (1–)2–15(–20 or more), variously arranged in loose to tight sometimes ± spike-like clusters at spinous nodes or on spineless stems; pedicels 4–11(–20) mm long, tomentellous. Petals narrowly obovate-elliptic, yellowish or blue-green, 4.5–6.5 mm long. Stamens 10. Ovary pubescent to tomentose; style 1–2 mm long. Fruit elongating markedly in early development, becoming ovoid to ellipsoid, usually rounded or truncate at both ends, usually ripening yellow, (2.3–)2.9–4(–4.5) x (1.3–)1.7–2.2(–2.5) cm.
