Acacia dimidiata Benth., London J. Bot . 1: 381 (1842)
Slender, resinous shrub or tree to 7.5 m high. Bark mottled grey, old bark brownish to dark grey, corrugated. Branchlets angular towards apices, yellowish, brown or grey-brown, squamulose, densely crisped-pubescent to tomentose, ribbed. Phyllodes obliquely ovate-rhomboidal, flat, 5.4–19 cm long, 20–90 mm wide (to 150 mm wide on young plants), rounded at base on upper side, tapering into pulvinus, with obtuse and mucronate apex, sparsely to moderately tomentulose-waxy especially between nerves, slightly vernicose, with 4 or 5 prominent nerves (sometimes with a few 3-nerved phyllodes) concurrent with lower margin near base (only the nerve closest to abaxial margin extending to mucro), with minor nerves reticulate; gland 1, prominent, basal. Spikes 2.5–7 cm long, golden. Flowers 5-merous; calyx 0.8–1.4 mm long, dissected to 1/2, with lobes slightly pubescent and with fimbriate margins; corolla 1.5–2.1 mm long, dissected to 1/2, glabrous; ovary densely tomentose. Pods straight, terete, 5.5–15.5 cm long, tapered towards base, crustaceous, densely puberulous, dehiscing from apex and curved back. Seeds longitudinal, oblong to narrowly oblong, 6–7.5 mm long, brownish black to black.
Occurs in extreme north-western Qld and through tropical N.T. Grows in open eucalypt woodland in sandy soil over laterite. Flowers July–Oct.
Allied to A. humifusa which has spikes 1–5 cm long, silky-hairy corollas, tomentose phyllodes and bracteoles conspicuous before anthesis.
Type of accepted name
South Goulburn Is., N.T., Aug. 1819, A.Cunningham 406 ; lecto: K, fide L.Pedley, Austrobaileya 1: 184 (1978); iso: BM n.v .
Acacia dimidiata is based on the following: A. dolabriformis A.Cunn. ex Hook., Icon. Pl. 2: t. 169 (1837), nom illeg ., non H.L.Wendl. (1820) nec Colla (1824); Racosperma dimidiatum (Benth.) Pedley, Austrobaileya 2: 348 (1987).
J.Brock, Top End Native Pl . 60 (1988); M.Simmons, Acacias Australia 2: 281 (1988); C.R.Dunlop, G.J.Leach & I.D.Cowie, Fl. Darwin Region 2: 10, fig. 4 (1995).
N.T.: 5 km S of Fergusson R. on Stuart Hwy, M.D.Tindale 6019 & C.Dunlop (CANB, K, NSW, Z); on road to Jabiru, 2 km N of Pine Creek, T. & J.Whaite 7981 (A, AD, CANB, MEL, NSW). Qld: Corinda–Westmoreland Stns, C.H.Gittins 1292 (NSW).