swamp wattle

Acacia elongata is an erect or spreading shrub that typically grows to a height of up to 5 m (16 ft), and has yellow-ribbed branchlets, sometimes with minute hairs pressed against the surface. Its phyllodes are rigid, linear to narrowly lance-shaped with the narrower end towards the base, straight to slightly curved, usually 50–160 mm (2.0–6.3 in) long and 24 mm (0.94 in) wide. The phyllodes are thinly leathery with 3 raised veins and a small gland near the base. The flowers are borne in two or three spherical heads in racemes 1–14 mm (0.039–0.551 in) long on peduncles 5–16 mm (0.20–0.63 in) long, each head 5 mm (0.20 in) in diameter with 20 to 42 light golden yellow flowers. Flowering occurs from July to October, and the pods are linear, straight, thinly leathery and glabrous, up to 90 mm (3.5 in) long, 3.5–6 mm (0.14–0.24 in) wide and strongly raised over the seeds. The seeds are broadly elliptic to oblong, 3–4 mm (0.12–0.16 in) long and glossy dark brown with an aril on the end.

Swamp wattle occurs in north-eastern New South Wales from near Kingscliff, south to near Eden and inland to Wagga Wagga in the west. It grows along watercourses and swamps in sandy soil in woodland and heath. The species has become naturalized in a few places in the Australian Capital Territory and Victoria.

Although it is not a widely cultivated species, smaller forms are sometime found in gardens. They grow quickly and flower within one or two years from seed. It is able to grow in a range of soils so long as they are reasonably moist and will manage in either full sun or dappled shade. It can be propagated by seed but requires pretreatment scarification or by soaking in boiling water. The shrub is suitable for poorly drained areas, will tolerate light frosts and salt spray.