Vachellia horrida subsp. horrida

Robber-Thorn is a shrub or small tree with spreading crown; branchlets black or brownish, round, hairless. Spines occur in pairs, 0.5-6 cm long, often fused at base, straight, ivory-white or often brown, the larger ones hollow and horn-like. Because of its huge thorns, it makes an excellent protective hedge, and that is probably the origin of its common name Robber Thorn. Leaves are double compound: axis 1-3 cm long, slender, sparsely yellowish finely velvet-hairy to hairless; leaf-stalks 0.5-1 cm long; glands solitary, more or less midway or occasionally near the base of leaf-stalk, circular, stalkless, 0.5-0.8 mm diameter; pinnae 2-5 pairs, 0.5-1.5 cm long, sparsely finely velvet-hairy to hairless; leaflets 6-15 pairs, nearly stalkless, linear or oblong, 0.8-4 x 0.4-1 mm, subequal or rounded at base, blunt to rounded or subacture at tip, firmly chartaceous, hairless, greenish or brown when dry; main vein prominent; nervules obscure. Inflorescences: in leaf-axils, spicate, solitary or 2-together, hairless, 2-5.5 mm long; flower-cluster-stalks 0.5-1 cm long. Flowers are creamy, white or yellowish, fragrant. Calyx is bell-shaped, 1-2 x 1.5-1.8 mm, hairless; teeth triangular or ovate, 0.5-0.8 mm long. Flowers are 2-3 mm long, hairless; petals 4-5, triangular, 1-1.5 x 0.6-1 mm. Stamens 3-4.5 mm long. Ovary is nearly stalkless, subspherical; about 1.5 mm diameter, style 3-3.5 mm long. Pods are sickle-shaped-oblong, 2.5-4.5 x 1-2 cm, flattened, inflated, straight to curved, unlobed, thin-walled, rounded to blunt at tip, hairless, prominently and transversely veined, dark reddish-brown or blackish when dry, stipe about 5 mm long; seeds 1-4, ovate to nearly round, flattened, 4.5-5.5 mm diameter. Robber Thorn is native to South India and SE Asia. Flowering: July-May.