About Vachellia tortilis (Forssk.) Galasso & Banfi
Vachellia tortilis (Forssk.) Galasso & Banfi shows significant variation in growth form based on growing conditions. In extremely arid environments, it grows as a small, wiry bush. In more favorable growing conditions, it can reach a height of up to 21 meters, or 70 feet.
Its leaves grow to approximately 2.5 centimeters (1 inch) in length, with between 4 and 10 pairs of pinnae. Each pinna bears up to 15 pairs of leaflets. Its most distinctive characteristic is its paired thorns: one thorn is long, straight and pale, while the paired second thorn is short, curved and dark. The small white flowers are strongly aromatic, and grow in tight clusters. Seeds develop in flat pods that coil into a spring-like shape.
This species is able to tolerate high alkalinity, drought, high temperatures, sandy and stony soils, and strongly sloped rooting surfaces. It can also withstand sandblasting. Individuals older than two years have demonstrated a level of frost resistance.
Vachellia tortilis is widespread across Africa, and has been recorded in Tunisia, Morocco, Uganda, Angola, Zimbabwe, Djibouti, and Botswana. It typically grows in regions where annual temperatures range from 0 to 50 °C (32 to 122 °F), and annual rainfall ranges from approximately 100 to 1,000 mm (3.9 to 39.4 in).
