Acacia deltoidea A.Cunn. ex G.Don, Gen. Hist. 2: 401 (1832)
Shrub 1.5–3 m high. Branchlets glandular-puberulous with intermixed longer hairs. Stipules persistent, subulate, partly united, 1.5–4 mm long, upcurved. Phyllodes imbricate, subsessile, patent to ascending, inequilaterally cuneate, elliptic, ovate, triangular or broadly obdeltate with gland-bearing angle on upper margin, 6–20 mm long, 4–7 mm wide, mucronate-pungent, coriaceous, glabrous or glandular-puberulous, with 3 or 4 distant, slightly raised main nerves and occasionally anastomosing secondary nerves; gland 1, rarely projecting beyond margin. Inflorescences simple, 1 per axil; peduncles normally 6–25 mm long, glandular-puberulous; heads globular, 5–6 mm diam., 56–73-flowered, dark golden. Flowers 5-merous; sepals 1/3–1/2-united. Pods oblong, slightly raised over seeds, straight, to 4.2 cm long, 10–12 mm wide, thin-coriaceous, obliquely reticulate-nerved. Seeds obliquely transverse, 5 mm long, dull, dark brown; aril apical.
Occurs in north-western W.A. in West Kimberley, in Bonaparte Archipelago and Napier Broome Bay areas and inland at Kimberley Downs Stn, Beverley Springs Stn and Phillips Ra.
Most closely related to A. adenogonia . Comprises two subspecies.
Most phyllodes broadest at or above middle, 4–6 mm wide
Most phyllodes broadest below middle, 5.5–7 mm wide
Acacia deltoidea A.Cunn. ex G.Don subsp. deltoidea
Phyllodes inequilaterally obdeltate, elliptic or triangular, mostly broadest at or above middle, 6–9 mm long, 4–6 mm wide, excentrically mucronate-pungent, coriaceous, glandular-puberulous, often obscurely so. Peduncles normally 6–12 mm long, glandular-puberulous, rarely with a bract about the middle; bracteoles exserted in buds.
Occurs in scattered populations in the Kimberley region of W.A. in the Buccaneer and Bonaparte Archipelago areas and near Cambridge Gulf, extending inland to Mt Barnett and Drysdale R. Natl Park. Grows in sand, usually on sandstone, in open shrubland and woodland.
Separated from subsp. ampla by dimensions, shape and apex of the phyllodes. Closely related to A. adenogonia and A. vincentii and related to A. stipulosa .
Type of accepted name
Montague Sound, W.A., 1820, A.Cunningham 293 ; lecto: BM, fide L.Pedley, Austrobaileya 2: 319, fig. 2J–N (1987), cf. also G.Bentham, London J. Bot. 1: 333 (1842); isolecto: K, US; probable isolecto: NSW.
F. von Mueller, Iconogr. Austral. Acacia dec. 7 [pl. 1] (1887), as A. stipulosa ; J.H.Maiden, J. & Proc. Roy. Soc. New South Wales 53: 202; pl. 13, figs 7–17 (1920); L.Pedley, loc. cit. , as Racosperma deltoideum ; R.S.Cowan & B.R.Maslin, Nuytsia 7: 203, fig. 1H–M (1990).
Racosperma deltoideum (A.Cunn. ex G.Don) Pedley, Austrobaileya 2: 315 (1987). Type: as for accepted name.
W.A.: creek entering inlet of Talbot Bay, 23 km SE of Cockatoo Is., P.A.Fryxell & L.A.Craven 3893 (CANB, PERTH); Manning Gorge, A.S.George 15176 (PERTH); above the headwaters of the Helby R., T.G.Hartley 14819 (PERTH); Prince Regent R. Reserve, K.F.Kenneally 2081 (K, MEL, PERTH).
Acacia deltoidea subsp. ampla R.S.Cowan & Maslin, Nuytsia 7: 206; 203, fig. 1N (1990)
Phyllodes inequilaterally elliptic to elliptic-ovate or triangular, mostly broadest below middle, 10–20 mm long, 5.5–7 mm wide, acute, mucronate, scarcely pungent, thinly coriaceous. Peduncles 18–25 mm long, glandular-puberulous, normally with narrowly lanceolate bract above middle; bracteoles not exserted in buds.
Known from two localities in the Admiralty Gulf area, W.A. Grows in woodland on sandstone.
The differences separating subsp. ampla from the typical subspecies are mostly quantitative but they combine to produce a quite different-appearing plant.
Type of accepted name
Lawley R. gorge, W.A., 29 July 1921, C.A.Gardner 996 (Forest Dept. no. 1496); holo: PERTH; iso: NSW, PERTH.
R.S.Cowan & B.R.Maslin, loc. cit.
W.A.: base of Bougainville Penin. on E shore of Admiralty Gulf, P.A.Fryxell et al. 4782 (BRI, CANB, PERTH).