Acacia subrigida Maslin, Nuytsia 10: 198 (1995)
Shrub to 2.5 m high. Branchlets glabrous. Phyllodes subsessile, erect, usually rhombic in section, straight to shallowly incurved, 8–15 cm long, usually 1–1.5 mm wide, with an indurate, dark brown, straight and erect mucro, smooth, subrigid, green to subglaucous, glabrous, 4-nerved but the adaxial nerve bifurcating near lowermost gland; nerves yellow; gland 3–17 mm above the much-reduced pulvinus, an obscure gland also at base of mucro. Inflorescences mostly 2–4-headed racemes; raceme axes mostly 2–10 mm long, glabrous; peduncles 1–2 cm long, glabrous; heads globular, 15–30-flowered, golden. Flowers 5-merous; sepals free, linear-spathulate. Pods narrowly oblong, raised over seeds, 6–11 cm long, 7–10 mm wide, chartaceous, light brown, glabrous. Seeds longitudinal to longitudinally oblique, ovate, sometimes oblong or elliptic, 5.5–7 mm long, shallowly depressed at centre, slightly shiny, black, exarillate.
Occurs in the Mukinbudin- Bonnie Rock (c. 45 km due NNE of Mukinbudin) area and near Maynard Hills (c. 100 km due SE of Sandstone), W.A. A variant from Shark Bay is discussed below. Grows in yellow sand in Acacia coolgardiensis tall shrubland.
Acacia subrigida Benth. (Shark Bay variant)
A variant occurring in red-brown sandy loam in the Shark Bay area (S of Carnarvon) is not included in the above description (e.g. c. 6 km W of Overlander- Denham road towards Tamala, B.R.Maslin 3682 , CANB, K, MEL, PERTH). It differs from typical A. subrigida mainly in the following ways: Phyllodes 11–21 cm long, 2 mm wide, flat but the midrib prominently raised (and sometimes rendering the phyllodes +/- terete). Racemes mostly 10–30 (-40) mm long; heads 24–39-flowered. Pods c. 13 mm wide. Seeds widely oblong-elliptic, 8 mm long, 7 mm wide.
Type of accepted name
20.5 km E of Mukinbudin towards Bullfinch, W.A., 13 Oct. 1975, B.R.Maslin 3965 ; holo: PERTH; iso: CANB, G, K, MEL, NSW, NY.
W.A.: 99.5 km SE of Sandstone on the road to Menzies, B.R.Maslin 5032 (PERTH); 1.5 km NE of Walyahmoning Rock, c. 60 km NW of Bullfinch, K.Newbey 9552 (PERTH).