Senegalia senegal (L.) Britton
Mimosa senegal L., Acacia senegal (L.) Willd.
Eng.: Gum acacia, gum arabic tree. Spa.: Acacia. Fre.: Gommier blanc. Ara.: Askab, aaschab, warwara, awarware (the last 2 in Niger). Tamahaq: Taazzet, tazzôêït, tall, ewarwar.
Shrub or tree up to 15 m in height, prickly, hermaphrodite, deciduous, usually multi-stemmed and with extended branches forming a lax crown, rounded or flattened to umbrella-shaped. Stems and main branches with rugose bark, brown or greyish-brown, which does not peel. Young branches with smooth bark, hairy. Prickles 2-8 mm, in groups of 3 at the nodes, the central one hooked and the lateral ones ± curved upwards (these are sometimes missing). Leaves 3-8 cm, alternate but often in fascicles of 2, bipinnate, usually hairy, with petiole with a gland towards the middle, and (1)2-8(12) pairs of pinnae —usually 3-6—, each with 7-25 pairs of leaflets 1-5(9) × 0.5-2(3) mm, linear or oblong, rounded at the apex and the base, subsessile, dull light green in colour, glabrous or sparsely hairy on both sides. Inflorescences spiciform, 2-12 cm long, briefly pedunculate —peduncle 6-10 mm—, white or whitish-yellow, solitary or in fascicles of 2-3, with glabrous or hairy rachis, and numerous minute flowers. Calyx 2-2.75(3.5) mm, campanulate, greenish, glabrous or somewhat hairy, with 5 triangular teeth, glabrous. Corolla 2.7-4 mm, tubular-campanulate, glabrous or subglabrous, with 5 oblong acute petals, creamy white. Stamens numerous, slightly fused at the base, with white to whitish-yellow filament. Pod (1.8)4-14 cm × 12-34 mm, linear-oblong, pendulous, not constricted between the seeds, highly compressed, ± rounded or pointed apex, greyish-brown or yellowish-brown, ± hairy or puberulous, dehiscent, with (2)4-8 seeds. Seeds 8-12 mm, orbicular, apiculate, compressed, light brown, with a dark pleurogram in V, smooth.
Flowering:
(July) August to November.
Fruiting:
October to February.
Habitat:
Savannahs and predesert environments, fossil dunes. It can withstand up to almost a year of drought and temperatures above 45° C; from sea level to 1,700 (1,950) m in altitude.
Distribution:
Widely distributed through arid and subdesert areas of Africa (Sahel, eastern and southern Africa) and SW of Asia, reaching towards the E to Pakistan. In North Africa, it is distributed throughout the southern Sahara and the Sahel, from Mauritania up to Sudan and Eritrea.
Observations:
A highly variable and taxonomically complex species. It is an important species due to its ability to fix dunes, and especially for the bark exudates, known as gum arabic, which was used in ancient Egypt in 4,000 BC.
Conservation status:
A relatively common and widely distributed species, not considered threatened. Currently, it has not been assessed at a global level in the IUCN Red List of Threatened Species. In Mali it is included in its List of species that need authorization for commercial use (Decree 07-155/P-RM of 2007).