Acacias of Australia

Print Fact Sheet

Acacia hamersleyensis Maslin

Common Name

Karijini Wattle, Hamersley Range Wattle




Mostly restricted to the Hamersley Ra. from near Newman W to near Wittenoom, Paraburdoo and Mt Wall (W of Tom Price), with an outlier in the Carnarvon Ra., Little Sandy Desert, W.A.


Spreading, bushy or openly branched, rounded or obconic, multistemmed shrub or tree 2–4 m high, the oldest plants sometimes gnarled, occasionally a spindly erect shrub with open crown and one or few main stems. New shoots pale citron-sericeous, soon glabrous. Branchlets yellowish to light brown or orange, sometimes pruinose, glabrous. Phyllodes narrowly elliptic, slightly asymmetric with upper margin more convex than lower, straight or shallowly falcate, (5-) 8–14 (–20) cm long, (5–) 7–17 (–25) mm wide, acuminate, coriaceous, glaucous to subglaucous, glabrous, multistriate by fine, close, non-anastomosing nerves with 1–3 slightly more prominent than the rest; pulvinus pale orange, mostly 5–10 mm long. Inflorescences simple, 1 or 2 per axil, often in false terminal racemes due to phyllode reduction; peduncles 3–7 mm long, thick, ±sparsely puberulous; spikes 3–6 cm long, 6–8 mm diam., densely flowered, golden. Flowers 5-merous; sepals 1/3–2/3-united; calyx tube white-villous. Pods narrowly oblong, to 8 cm long, 5–8 mm wide, firmly chartaceous, slightly undulate, straight to irregularly shallowly curved, short-pilose with hairs pale golden ageing white. Seeds oblique, oblong to elliptic, 4–4.5 mm long, ±glossy, grey-brown; aril cream coloured (pale yellowish when dry).


Flowers June–Sept., the main flush July–Aug.


Found in iron-rich soils on ridges and upper slopes of ranges, sometimes forming groves along watercourses descending from ranges, growing with Acacia spp. and Eucalyptus spp. in spinifex country.


W.A.: upper slopes of Mt Nameless, Tom Price, K.Atkins 1225 (K, PERTH) and 1240 (MEL, PERTH); Wittenoom Gorge, 4 km S of township, B.R.Maslin 4630 (PERTH); Rhodes Ridge, 53.5 km NW of Newman on road to Juna Downs, B.R.Maslin 4609 (PERTH); Mt Whaleback, Newman, K.Walker 95 (CANB, MEL, NSW, PERTH).


Related to, and until recently confused with A. bromilowiana (see that species for distinguishing features). May superficially resemble A. citrinoviridis, A. fecunda, A. tumida var. pilbarensis and A. xiphophylla (see those species for distinguishing features). Acacia daweana may have originated as a hybrid between A. effusa and A. hamersleyensis.

FOA Reference

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


Edited by B.R.Maslin

R.S.Cowan, B.R.Maslin