Acacia tortilis (Forssk.) Hayne  

Tall shrubs sometimes seen as tup to 6 m. high (rarely taller), with a flat-top canopy. Branches yellowish-brown. Stipular spines of two kinds; the long ones up to 6 cm or even longer, white, brown-tipped, the short usually 1 cm or less, more or less falcate or hooked downwards, reddish dark-brown or the lower parts white. Leaves borne in axillary clusters on both older and younger branches, densely pubescent; pinna-pairs usually 2 to 6 (rarely more), each pinna with usually 6 to 12 pairs of leaflets (rarely more): rachii sparingly or densely pubescent, each with usually 2 sessile glands and ending in a short appendage beyond the last pinna-pair, leaflets minute, rarely exceeding 3 mm in length. Flowers in white to creamy-white globular heads about 8 mm across, peduncles about 1.5 cm long: involucel almost at the base of the peduncle. Calyx about 1.5 mm long: involucel almost at the base of the peduncle. Corolla about 2.5 mm long, 5-lobed, glabrous. Pods most often spirally contorted or twisted, green, reddish-tinged, densely pubescent, up to about 15 cm long (usually shorter), usually 5 mm or less wide, often constricted between seeds. In some locations (e.g. Hakima near Abu Arish) severe insect infestation makes the pods appear inflated, thicker and straight.