Acacias of Australia

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Acacia ridleyana W.Fitzg.




Occurs from the Murchison R. S to Northampton and at Mogumber, south-western W.A.


Sprawling spreading shrub 0.2–0.9 m high. Branchlets obviously hirsutellous to pubescent, rarely glabrous. Stipules persistent, narrowly triangular, to 2.5 mm long. Phyllodes ascending to erect, narrowly oblong to linear-oblanceolate, ±sigmoidally curved, sometimes straight, 12–25 mm long, 2–3.5 mm wide, coriaceous, with indumentum as on branchlets but sometimes only raised hair-bases evident, with normally 3 distant, strongly raised nerves per face; tip curved or occasionally straight, acute to subobtuse, typically obliquely and ±pungent. Inflorescences simple, 1 per node; peduncles (8–) 10–20 mm long, with indumentum as on branchlets; heads globular, 5–7 mm diam., 16–30-flowered, ±golden. Flowers 5-merous; sepals free, 1/2–3/4 petal length. Pods compressed-cylindrical, ±curved, to 5.5 cm long, 3.5–4 mm diam., rigid-coriaceous, finely longitudinally striate, with indumentum as on branchlets. Seeds longitudinal, ovate, ±2.5 mm long, mottled darker and lighter brown, arillate.


Grows in sand, clay and loam, mostly in heath.


W.A.: 2 km S of Mogumber, A.Coates S4463 (PERTH); Gillingarra, R.J.Cumming 1550a (PERTH); 10 km N of Mogumber, B.R.Maslin 5052 (CANB, K, MEL, PERTH); 13 km due NNE of Gregory, B.R.Maslin 6267 (PERTH).


Seems most closely related to A. cavealis. Also superficially similar to A. auronitens which has regularly single-nerved glabrous phyllodes, spinescent stipules, larger flower-heads and longer, thick, flat, very woody pods with very broad, pale-coloured margins. Also possibly related to A. wilsonii.

Two collections from the region in which the type collection was made are completely glabrous (i.e. R.J.Cumming 1550a and A.Coates S4463).

FOA Reference

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


R.S.Cowan, B.R.Maslin

Minor edits by J.Reid