Acacia cowleana Tate, Rep. Horn Exped. Central Australia 3: 157, 187 (1896)
Shrub or tree to 8 m high; crown densely foliaged. Branchlets prominently angled at extremities, becoming terete with age, minutely sericeous, rarely glabrous. New shoots at initiation encrusted with dark brown resin that obscures the underlying appressed indumentum, rarely glabrous. Phyllodes shallowly to moderately falcate, rarely dimidiate, 8–20 cm long, 14–36 mm wide, coriaceous, minutely sericeous, rarely glabrous; longitudinal nerves numerous, 2 or 3 per mm, with 3 more evident than the rest and the lowermost 2 running together at base of phyllode, minor nerves occasionally anastomosing. Inflorescences 1 or 2 per axil, simple or vestigial binate racemes with axes to 2 mm long; peduncles 3–10 mm long, sericeous, rarely glabrous; spikes 3–5 cm long, golden; bracteoles spathulate, 0.7 mm long. Flowers 5–merous; sepals united; ovary hairy, rarely glabrous. Pods linear, straight to shallowly curved, 3.5–5 mm wide, chartaceous to coriaceous, very sparsely minutely hairy or glabrous. Seeds longitudinal, oblong, 3.5–5 mm long, glossy, dark brown to black; aril yellow. 6 n = 78, fide L.A.J.Thomson, pers. comm.
Acacia cowleana has a discontinuous distribution in the northern arid zone between latitudes 20–25S. Its main area of occurrence extends from the W.A.–N.T. border to central Qld and S into central-northern N.S.W. in the Enngonia–New Angledool area. In W.A. it occurs mainly in the Pilbara region. Grows mainly along the banks of seasonal creeks. Flowers June–Aug.
Closely related and previously confused with the tetraploid species A. elachantha . For example, in L.Pedley, Austrobaileya 1: 95–96, 98–99 (1978), the A. cowleana description represents A. elachantha while the A. oligophleba description represents typical A. cowleana . An apparently rare glabrous variant of A. cowleana occurs in the Laglan–Jericho region, Qld. Hybrids between A. cowleana and A. holosericea have been collected from Coorajah Ck, Budgerygah Stn, Qld, fide M.W.McDonald & B.R.Maslin, Austral. Syst. Bot. 10: 311 (1997) . The distinguishing characteristics of A. cowleana and its closest allies, A. colei , A. elachantha , A. leptocarpa , A. longispicata and A. thomsonii , are given by M.W.McDonald & B.R.Maslin , op. cit. 306, 307 & 311.
This species has been rarely cultivated compared to its close relative A. elachantha . The information given under A. cowleana in J.C.Doran & J.W.Turnbull (eds), Austral. Trees & Shrubs: species for land rehabilitation and farm planting in the tropics 134–135 (1997) and P.Latz, Bushfires & Bushtucker 94 (1995) is mainly attributable to A. elachantha .
Type of accepted name
Slopes of Mt Tate, N.T., June 1894, R.Tate s.n .; lecto: MEL, fide M.W.McDonald & B.R.Maslin, op. cit. 304; isolecto: AD, ?K.
Racosperma cowleanum (Tate) Pedley, Austrobaileya 2: 347 (1987). Type: as for accepted name.
Acacia oligophleba Pedley, Austrobaileya 1: 174, fig. 8D (1978); Racosperma oligophlebum (Pedley) Pedley, Austrobaileya 2: 353 (1987). Type: North Kennedy District: 7 miles [11.2 km] from Pentland on road to Torrens Creek, Qld, 9 June 1966, L.Pedley 2121 ; holo: BRI; iso: K n.v .
B.R.Maslin, in J.Jessop (ed.), Fl. Centr. Australia 125, fig. 161G (1981); B.R.Maslin & L.A.J.Thomson, Austral. Syst. Bot . 5: 735, fig.3 (1992); M.W.McDonald & B.R.Maslin, op. cit. 305, fig. 1 & 309, fig. 2 (1997).
W.A.: Fortescue, Marra Mamba, Hamersley Ra., J.V.Blockley 319 (PERTH). N.T.: Old Tennant Creek telegraph stn, c. 13 km N of Tennant Creek township, B.R.Maslin 7461, M.McDonald & G.Leach (PERTH, DNA); Qld: Gilruth Plains (N Brandy) c. 50 km ESE of Cunnamulla , M.G.Brooker B220,221 (NSW). N.S.W.: ‘Beulah’, Enngonia, 27 Sept. 1983, G.Cunningham s.n. (NSW).