Acacia oligoneura F.Muell., J. Proc. Linn. Soc., Bot . 3: 139 (1859)
Many-stemmed, resinous shrub to 2 m high. Branchlets angular, flattened towards apices, greenish yellow or yellow to pale brown, glabrous, often scurfy and with numerous to scattered reddish brown to clear granules. Phyllodes very narrowly oblanceolate (-elliptic), straight or slightly curved, (6–) 10–16 (–19) cm long, (7–) 8.5–16 (–20) mm wide, chartaceous to thinly coriaceous, light olive-green, glabrous, with yellowish nerves, the lower 2 of the 3 prominent, longitudinal nerves confluent near base, the other main nerve often confluent with upper margin, with 2–4 (–5) nerves per mm, moderately to strongly anastomosing; gland basal, 0–4 mm above pulvinus. Peduncles 2.5–8 mm long. Spikes 1–3 in axils, 1–4.2 cm long, light golden or bright yellow. Flowers 5-merous; calyx cupular, membraneous, 0.5–0.7 mm long, dissected to 1/5–1/2, glabrous or with reddish brown glandular hairs (granules) towards sepal apices; corolla 1–1.5 mm long, dissected to 1/2 or more. Pods narrowly oblanceolate-linear, basally narrowed, flat, 5–8.5 cm long, 4–7.5 mm wide, woody, prominently obliquely to longitudinally nerved, glabrous, opening elastically from hooked apex. Seeds oblique, elliptic or oblong, 4.7–5.5 mm long, mid-brown; funicle-aril narrowly conical.
Known from the Kimberley region of W.A. and from Noonamah (S of Darwin) to the Litchfield–Daly River area and the Victoria River area of north-western N.T. Grows in woodland, on rocky slopes, in laterite or red clay over basalt (Mitchell Plateau). Flowers Jan.–May, fide C.R.Dunlop, G.J.Leach & I.D.Cowie, Fl. Darwin Region 2: 16, fig. 8 (1995).
Branchlets and phyllodes usually with reddish brown granules which also occur on bracteole laminae and sepal apices. Related to A. oncinocarpa which is distinguished usually by more elliptic phyllodes (broadest near middle) with more closely spaced, less anastomosing longitudinal nerves, and by paler inflorescences.
Dunlop et al ., loc. cit ., report that thin stems arise from a woody rootstock after fire.
Type of accepted name
In terra Arnhem’s Land prope MacAdam’s [MacAdam] Ra., [N.T.], Oct. 1855, F.Mueller 96 ; syn: K, MEL; Victoria R., [N.T.], F.Mueller 95 ; syn: K.
Illustration
C.R.Dunlop et al ., loc. cit .
Representative collections
W.A.: about 0.5 km N of CRA mining camp, Mitchell Plateau, B.R.Maslin 5084 (BRI, NSW, PERTH); 0.5 km N of mining campsite, Mitchell Plateau, N Kimberley, K.F.Kenneally 8168 (BRI, PERTH); N.T.: Litchfield Natl Park, track to Lost City, I.D.Cowie 5372 & L.Taylor (BRI n.v ., DNA n.v ., PERTH n.v .); Daly River road, G.Wightman 345 (DNA, PERTH).
(NSW)
The information presented here originally appeared on the WATTLE CD-ROM which was jointly published by the Australian Biological Resources Study, Canberra, and the Department of Parks and Wildlife, Perth; it was produced by CSIRO Publishing from where it is available for purchase. The WATTLE custodians are thanked for allowing us to post this information here.
