Acacia pterocaulon Maslin, Nuytsia 10: 165 (1995)
Intricate shrub to 1.3 m high. Branchlets glabrous. Phyllodes continuous with branchlets, bifariously decurrent and forming opposite wings with each one extending to the next below, the wings 2- 6 mm wide, coriaceous, subglaucous, glabrous, with marginal nerve prominent; free portion of phyllodes erect, lanceolate to narrowly triangular, straight or very shallowly incurved, 1–5.5 cm long, with main nerve central; gland basal. Inflorescences racemose; raceme axes 1–10 cm long, normally narrowly winged at anthesis; peduncles 10–15 mm long, glabrous; heads globular, 10–15 mm diam. at anthesis (dry), densely 60–70-flowered, golden. Flowers 5-merous; sepals free, linear-spathulate. Pods linear, to 12 cm long, 4–5 mm wide, coriaceous-crustaceous, pruinose, glabrous. Seeds longitudinal, oblong, 4.5–5 mm long; aril subconical.
Known only from within a range of hills W of Morawa, W.A. Grows in rocky (chert) clay loam on slopes of hills, in Eucalyptus woodland or dense casuarina scrub.
Vegetatively resembling the more southerly distributed A. glaucoptera and some forms of A. willdenowiana but readily distinguished by its linear, straight pods which are 4–5 mm wide. Additionally, A. glaucoptera is recognised by its much smaller flower-heads, extremely reduced 1-headed racemes (to 0.5 mm long) and densely tomentulose phyllode axils. Acacia willdenowiana is further recognised by its rush-like growth habit, pale yellow to white heads with 13–21 flowers, gamosepalous calyx and transverse seeds.
Type of accepted name
24 km from Morawa towards Three Springs, W.A., 1 Sept. 1976, B.R.Maslin 4273 ; holo: PERTH; iso: CANB, K, MEL, NY.
W.A.: type locality, R.J.Cumming 2194 (MELU, NSW, PERTH).