Acacias of Australia

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Acacia nervosa DC.

Common Name

Rib Wattle




Occurs from Mogumber S to Lake Muir and Cape Naturaliste, with outlying occurrences near Tammin, Katanning and Mount Barker, south-western W.A.


Glabrous subshrub 0.1–0.5 m high, sometimes sprawling, single- or multistemmed from a woody root-stock. Branchlets prominently ribbed, pruinose. Stipules (2–) 3–8 (–10) mm long, spreading, slender, spinose. Phyllodes slightly inequilateral, narrowly elliptic, straight or shallowly incurved, 1–5 cm long, 4–12 (–16) mm wide, commonly acute, ±pungent, greyish green; midrib and marginal nerves prominent; lateral nerves obscure or absent; gland 2–12 mm above base. Inflorescences 2–4-headed often rudimentary racemes with axes 0.5–7 (–10) mm long; peduncles 5–18 mm long; heads showy, prolific, globular, loosely 7–12-flowered, bright golden. Flowers 4-merous; sepals c. 3/4-united, with lobes broadly triangular. Pods narrowly oblong, twisted, to 5 cm long, 8–9 mm wide, ±woody, dark brown; margins thick. Seeds transverse, oblong to ±circular, 3.5–4 mm long, shiny, greyish brown; funicle flat and dilated at attachment to pod; aril dark brown (dry).


Grows in laterite or gravelly sand or sandy clay, frequently near watercourses, in Eucalyptus woodland or forest.


W.A.: Western Australia, J.Drummond 1: 290 (BM, G, K, OXF, P); Mogumber, Sept. 1936, C.A.Gardner s.n. (PERTH); Tammin, July 1951, B.J.Grieve (PERTH); 35.3 km S of Kojonup on road to Rocky Gully, B.R.Maslin 642 (MEL, PERTH); Murray district, E.Pritzel 483 (BM, M, NSW, P, Z); Katanning, F.Stoward 172 (BM)


Differs from other members of the ‘A. myrtifolia group’ by its transverse seeds, and the dilated funicle is otherwise known only in A. durabilis. Other dwarf members of the group include A. obovata and A. pygmaea.

FOA Reference

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


Minor edits by J.Rogers