Acacia retrorsa Meisn., Bot. Zeitung (Berlin) 13: 10 (1855)
Sprawling, prostrate, multistemmed shrub with rather slender branches to 1 m long. Branchlets green, finely yellow-ribbed, glabrous, sometimes hirsutellous. Phyllodes sessile, strongly retrorse, sometimes some patent, linear, straight to shallowly curved, pentagonal-terete to flat, 15–25 mm long, 1–2 mm wide, pungent, green, glabrous, 5-nerved, the 2-nerved adaxial margin 0.3–0.5 mm wide and nerve-like when dry; midrib prominent. Inflorescences 1-headed rudimentary racemes with axes <0.5 mm long; peduncles 3–5 mm long, glabrous; basal bracts persistent; heads globular, 16–24-flowered, light golden. Flowers 5-merous; sepals c. 2/3-united. Pods submoniliform, to 6 cm long, 3.5–4.5 mm wide, firmly chartaceous, dark brown, glabrous. Seeds longitudinal, oblong to elliptic, c. 4 mm long, blackish except for yellowish centre; aril clavate.
Restricted to between Jurien Bay and Eneabba, south-western W.A. Grows in gravelly sand in low open heath or low open woodland.
Inflorescence morphology suggests affinities to the ‘ A. pravifolia group’, but the venation of the phyllodes is very different from other members of that group. Superficially similar to A. declinata .
Type of accepted name
Between Moore and Murchison Rivers, W.A., J.Drummond 6: 4 ; syn: BM, CGE, K, LD (sphalm. ‘coll. 3’), OXF, P, PERTH (Fragment, origin unknown), W; see B.R.Maslin & R.S.Cowan, Nuytsia 9: 411 (1994), for note on types.
Synonymy
Acacia sphacelata var. retrorsa (Meisn.) Benth., Fl. Austral . 2: 331 (1864). Type: as for accepted name.
Representative collections
W.A.: c. 10 km N of Coorow- Green Head road towards Eneabba, 2 Sept. 1979, C.Chapman s.n. (MEL, PERTH); Swan R., J.Drummond 299 (G-DC, K); c. 19 km E of Jurien Bay, B.R.Maslin 2625 (PERTH).
(BRM)