Acacia scopulorum Pedley, Austrobaileya 5: 319 (1999)
Tree or large shrub, branches sometimes sprawling, to 5 m high. Branchlets dark red, angular, glabrous. Phyllodes narrow, lanceolate falcate, widest above middle, 7–11 cm long, 4.5–6 mm wide, glabrous; apex with callus point, sometimes oblique; longitudinal nerves 8–14, widely spaced, with an occasional anastomose; gland basal; pulvinus 1.5–2.5 mm long. Spikes paired in upper axils, interrupted, 3.5–4.5 cm long, yellow; peduncles 1.5–2 mm long. Flowers 4-merous; calyx 0.5 mm long, shortly lobed, glabrous except for a few hairs on lobes; corolla lobed to level of calyx, c. 1.5 mm long, strongly reflexed; stamens c. 2.5 mm long; ovary glabrous. Pods glabrous, linear, straight or slightly curved, to 9 cm long, 2 mm wide, reticulately veined, with thickened margins, raised over seeds. Seeds longitudinal, obloid, 2–2.5 mm long, 1.5–1.7 mm wides; aril small, cupular, yellow.
Restricted to the upper catchments of eastern tributaries of Nourlangie Ck, Kakadu Natl Park, N.T. Found in sand and gravel on gentle slopes and in crevices on sandstone pavements. Flowers collected Jan. & Apr.; fruits collected Mar. & Apr.
The relationships of A. scopulorum are not at all clear. In general appearance it resembles A. spirorbis and A. leptostachya , and has been distributed from DNA as the latter, but differs from both in its small 4-merous flowers. On the other hand, it does not appear to be particularly close to the 4-merous juliflorous species of south-eastern Australia.
Type of accepted name
ESE of Mudginbarry, N.T., 1236’S, 13258’E, 19 Feb. 1973, C.R.Dunlop 3313 ; holo: BRI; iso: CANB n.v. , DNA n.v. , MEL n.v .
N.T.: Radon Ck, Mt Brockman, C.R.Dunlop 4679 (BRI, DNA); Deaf Adder Gorge, R.E.Fox 2433 (BRI, DNA); Arnhem Land Plateau, upper catchment of Magela Ck, I.D.Cowie 5616 & K.Brennan (BRI, DNA, PERTH); Mt Brockman Outlier, 15 km SE of Jabiru, R.W.Johnson 4797 (BRI, CANB, DNA, MEL, NSW).