Acacia orthotricha Pedley, Contr. Queensland Herb . 11: 19 (1972)
Shrub less than 1 m high. Stems pubescent with long, spreading to reflexed or erect hairs. Stipules 0.7–1.5 mm long. Phyllodes in whorls of 7–11, slightly incurved, recurved at apex, slightly flattened and deeply sulcate above, 4–7.5 mm long, shortly mucronate, pubescent with erect hairs. Peduncles 5–10 mm long, pubescent. Heads 25–35-flowered. Flowers 5-merous; calyx 0.9–1.6 mm long, finely but distinctly ribbed, the lobes broadly triangular, obtuse, acuminate or laciniate, with some long hairs on margins; corolla lobes striate, hairy towards apex. Pods linear, to 60 mm long, 9–13 mm wide, glabrous but viscid. Seeds transverse or slightly oblique, c. 5 mm long, not seen mature.
Occurs between Mt Elizabeth Stn, Tableland Stn and Kununurra, W.A., and on Inverway Stn, N.T. Grows on plains in lateritic soil, in open shrubland.
A very distinct species with indumentum and calyx similar to A. chippendalei , but it has markedly larger flowers and heads and transverse seeds. The arrangement of the seeds suggests some affinity with A. adoxa which, however, has shorter hairs on the branchlets and phyllodes and a calyx with linear, not broadly triangular lobes.
Type of accepted name
20 miles [32 km] W of Inverway Stn, N.T., June 1952, R.A.Perry & M.Lazarides 2929 ; holo: BRI; iso: CANB, NT, PERTH.
L.Pedley, op.cit. 3 fig. 1f.
W.A.: Kununurra, June 1966, A.Douglas (PERTH); Mt Elizabeth Stn, J.Petheram 425 (PERTH); 7 km NE of Tableland Stn on Marion Downs track, T.Willing 502 (PERTH). N.T.: 33 km W of Inverway Stn, G.M.Chippendale NT5943 (BRI, NT).