Acacias of Australia

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Acacia costata Benth.




Occurs in an area between Walebing, Calingiri and Cataby, with an early collection from near Perth, south-western W.A.


Spreading shrub normally 0.2–0.5 m high. Branchlets ribbed, tomentulose to woolly, glabrescent. Stipules setaceous, 1.5–3 mm long. Phyllodes subsessile, ±patent, inequilateral, narrowly lanceolate, straight or shallowly recurved, 6–15 mm long, 1.5–2.5 mm wide, acuminate, pungent, rigid, green, often sparsely tomentulose on nerves, 5-nerved, with the 2-nerved adaxial margin convex, thick and nerve-like; midrib prominent and near the non-thickened abaxial margin. Inflorescences simple, 1 per axil; peduncles 5–12 mm long, sparsely to densely appressed-puberulous; heads globular, rather loosely 13–19-flowered, golden; bracteoles dark brown, tomentulose; buds large. Flowers 5-merous; sepals united at base, dark brown, tomentulose; petals striate, glabrous. Pods curved, terete, to 5 cm long, 4–4.5 mm diam., dark reddish brown, obscurely striate, minutely appressed-puberulous. Seeds longitudinal, c. 5 mm long; aril terminal, conical.


Grows in sand or laterite, commonly in low heath.


W.A.: 10 km S of Calingiri, P.Hussey 15 (PERTH); 28 km W of Mogumber on Mogumber West Rd to Brand Hwy, B.R.Maslin 5480 (CANB, PERTH); sand near Perth, A.Oldfield s.n. (K).


Most closely related to A. barbinervis. Resembling A. rigida in phyllodes and pods.

The Drummond specimens with flowers resembling A. divergens which are noted by G.Bentham, Fl. Austral. 2: 327 (1864), under A. costata, are A. acutata.

FOA Reference

Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia