Acacia hopperiana Maslin, Nuytsia 12(3): 495 (1999)
Dense shrub 1–3 m tall, occasionally a tree to 4 m. Branchlets red-brown (yellow-orange at extremities), silvery sericeous between the fine ribs, normally glabrescent. Phyllodes terete, innocuous to coarsely pungent, 6–14 cm long, 0.7–1 mm wide, sub-rigid, straight to shallowly incurved, ascending to erect, light green, appressed-puberulous when young, glabrous or with hairs confined to furrows between nerves when mature; longitudinal nerves 10, of uniform width (0.2–0.3 mm wide) and prominence, flat-topped or shallowly convex, each separated by a very narrow, shallow, dark longitudinal furrow. Gland inconspicuous, sometimes absent, 1–6 cm above pulvinus. Inflorescence simple; peduncles 1–2 mm long; spikes 10–20 (–25) mm long, golden. Flowers 4-merous; calyx gamosepalous. Pods 5–9 cm long, 2–3 mm wide, flat, moderately to deeply constricted between seeds, thinly coriaceous–crustaceous to firmly chartaceous, straight to shallowly curved, greyish brown; margins narrow, thickened. Seeds longitudinal, obloid/ellipsoidal or discoid, 2–3 mm long, 1.5–2 mm wide, glossy, mottled or not; aril obvious, conical and white.
Occurs in south-west W.A. between Carnamah and Watheroo, at Buntine Rock (c. 20 km N of Wubin), and north of Geraldton from Nerren Nerren Stn south to about 10 km north of the Murchison River. North of the Murchison it grows in yellow or reddish sand on plains or in swales between sanddunes; around Coorow it grows in yellow sand, while at Buntine Rock it grows in gritty loam soil fringing the rock.
Seeds on plants occurring north of Geraldton are clearly discoid and the aril readily detaches from them. On plants south of Geraldton, however, the seeds are obloid/ellipsoidal and the aril does not so readily detach.
Closely related to A. isoneura and care is needed not to confuse the two. Acacia isoneura is most reliably recognized by its 8-nerved phyllodes with an obscure gland situated 0–3 mm above the pulvinus, reddish brown pods and ellipsoidal to obloid-ellipsoidal seeds (never discoid).
Type of accepted name
44 km N of Murchison R. on North West Coastal Highway, W.A., 3 Aug. 1974, B.R.Maslin 3650; holo: PERTH; iso: CANB, K, MEL - all distributed as A. isoneura subsp. nimia .
W.A.: 22.8 km S of Billabong Roadhouse, North West Coastal Hwy, M.E.Ballingall 1894 (PERTH); Winchester area, 19 Aug. 1972, C.Chapman s.n. (PERTH); 70 km N of Northampton, R.Hnatiuk 760473 (PERTH); 45 km N of Murchison R., North West Coastal Hwy, B.R.Maslin 3345 (CANB, G, K, NY, PERTH); Buntine Rock, NNW of Wubin, B.R.Maslin 7605 (CANB, K, MEL, PERTH) and S.D.Hopper 8337 (BRI, NSW).
This species is not included in Fl. Australia ; the above treatment was abstracted from the original description.