flat-stemmed wattle

Acacia complanata is a shrub or tree that typically grows to a height of up to 5–6 m (16–20 ft) and has downwards arching branches. Its branchlets are more or less winding, flattened, narrowly winged and glabrous. The phyllodes are narrowly elliptic, mostly 50–100 mm (2.0–3.9 in) long and 10–30 mm (0.39–1.18 in) wide, thinly leathery and glabrous with 7 to 9 prominent veins. The flowers are borne in 4 to 8 spherical heads in axils on peduncles 8–12 mm (0.31–0.47 in) long. The heads are about 6 mm (0.24 in) in diameter with mostly 35 to 45 bright yellow flowers. Flowering occurs roughly from November to March, and the pods are linear, thinly leathery to crusty, glabrous, up to 150 mm (5.9 in) long, 6–10 mm (0.24–0.39 in) wide and rounded over the seeds. The seeds are more or less spherical, dull, dark brown and 4–5 mm (0.16–0.20 in) long.

Flat-stemmed wattle is widely distributed throughout south-eastern Queensland from around Jericho in the west to around Bundaberg in the east and is also found as far southwest as the Dumaresq River in New South Wales and down the north coast to around Coffs Harbour, New South Wales. It is grows on low ridges in gravelly, sandy to loamy soils, often over sandstone, and usually in heathland or dry sclerophyll forest. It also occurs in a disjunct population near Torrington.

This species of wattle is an ideal suburban garden species, rewarding the gardener with flowers several times a year. It can be pruned to a desired shape and recovers from fire from a lignotuber. It is easily propagated from seed, following treatment by soaking in boiling water or by scarification.