Description

Key Characters:

Growth Form: Shrubs or trees 3–10 m tall.

Stems: Branches slightly zigzag, with stout stipular spines 1–3(–5) cm long.

Roots:

Leaves: Leaves compound. Alternate. Leaves with 1–2(–4) pairs of pinnae, each with (6–)12–25(–29) pairs of leaflets; Leaflets oblong, 6–16(–23) mm long, 1.5–3.2(–5.5) mm wide. Apex rounded, obtuse, or subacute. Base rounded. Surfaces glabrous, rachis with a small nectary gland below each pair of pinnae, with leaflets, with a nectary between each pair of leaflets. Leaflet margins entire. Petiolate. Stipules present as spines 1-3(-5) cm long.

Flowers: Flowers numerous, in cylindrical spikes 5–10(–15) cm long. Flowers mimosaceous, bisexual (perfect). Calyx campanulate, shortly 5-toothed. Corolla of 5 petals, corolla pale yellow, 4–5 mm long. Stamens 5–8 mm long. Ovary superior, stipitate; ovules numerous.

Fruit: Pods pale yellowish brown; cylindrical or slightly irregularly curved; usually 8–30 cm long; 0.8–1.7 cm in diameter; mesocarp fleshy; only flattened in younger stages; stipe 0.7–2 cm long; septate between the seeds. Seeds obovoid; 5–6.5 mm long; 4–5 mm wide; numerous slightly laterally compressed; with a horseshoe–shaped areole and copious endosperm.

Ploidy: 2n = 26; 28; 52; 56

Habitat: Arid and coastal areas.

Elevation Range: 0–10 m.