Acacia proiantha Pedley, Austrobaileya 5: 318 (1999)
Erect spindly shrub to 6 m tall, sometimes flowering when less than 1 m. Branchlets angular, glabrous, slightly resinous. Phyllodes linear, 11–17.5 cm long, 1–1.5 mm wide, acute with a deciduous callus point, rather thick, glabrous; one longitudinal nerve forming a midrib, with 4–6 less prominent non-anastomosing nerves on each side of it; gland basal, inconspicuous; pulvinus 1.5–3 mm long. Spikes single at base of rudimentary axillary shoot, 15–20 mm long, rather open, yellow; peduncles 4–6 mm long, resinous. Flowers 5-merous; calyx broadly cupular, 0.4–0.6 mm long, lobed to middle, somewhat resinous, sometimes with a few marginal hairs; corolla 0.8–1.1 mm long, lobed to middle, glabrous; ovary glabrous, resinous. Pods straight, linear, acute, to 6.5 cm long, 2.5 mm wide at widest part, 1.5 mm wide at isthmuses, glabrous, slightly resinous; valves rather thick with raised reticulate nerves, constricted between seeds and raised over them. Seeds longitudinal, obloid, c. 2.6 mm long, 1.6 mm wide; aril pale yellow, folded twice beneath seed.
Restricted to the headwaters of the South and East Aligator Rivers, Kakadu Natl Park, N.T. Occurs on gentle slopes in sandy soil and in crevices in sandstone pavements where it is often common. Flowers collected Feb. & July; fruits collected Feb.
Acacia proiantha is not closely related to any other species of Acacia sect. Juliflorae . It has long narrow phyllodes with one nerve more prominent that the rest, forming a distinct midrib; its flowers are small with petals only about 1 mm long; and its pods are somewhat moniliform with small longitudinal seeds.
Type of accepted name
c. 2.5 miles [4 km] SW of Mt Gilruth, N.T., 1303’S, 13302’E, 28 Feb. 1973, M.Lazerides 7938 ; holo: BRI; CANB n.v .
Representative collections
N.T.: 5 km E of Jim Jim Falls, N.B.Byrnes 2724 (BRI, DNA, K); Deaf Adder Gorge, R.E.Fox 2519 (BRI, DNA).
(LP)