Acacia stenoptera Benth.
Acacia stenoptera Benth.
Fabaceae
Occurs from near Mingenew S to Mount Barker, south-western W.A.
Subshrub to 0.5 m high, occasionally taller, often straggly. Branchlets angled, usually glabrous. Phyllodes continuous with branchlets, usually forming narrow stem wings 0.5–3 mm wide; free portion of phyllodes flat to compressed, straight or recurved, usually (0.5–) 1–3 cm long, 1–4 mm wide, pungent, green, usually glabrous; midrib prominent; upper margin flat, 2-nerved; gland not prominent, near base. Inflorescences simple, 1 or 2 per axil; peduncles (2–) 3–10 (-20) mm long, glabrous or appressed-puberulous; heads globular, large, rather loosely 7–12-flowered, cream to golden; buds large, acute or apiculate. Flowers 4‑merous; sepals united; petals flabellate-striate. Pods long-stipitate, to 10 cm long, 5–10 mm wide, thinly coriaceous-crustaceous, reddish, glabrous; margins winged. Seeds oblique, ±oblong, 5 mm long; aril terminal, conical.
Grows in sand and laterite, in heath, scrub, woodland and open forest.
W.A.: c. 14.5 km from Three Springs towards Eneabba, E.M.Canning WA/68 3343 (PERTH); Swan R., J.Drummond 2: 145 (BM, CGE, E, G, K, LUND, NSW, OXF, P, W); c. 14.5 km N of Mount Barker on Albany Hwy, S.Paust 12 (PERTH); Sussex district [between Capel and Toby Inlet], L.Preiss 992 (C, G, GOET, HBG, K, L, LUND, MO, NAP, P, RO, STR, W); 44.9 km N of Bindoon on Great Northern Hwy, M.D.Tindale 1268 (K n.v., MEL n.v., NSW, PERTH: variant).
A very variable species. Branchlet and phyllode nerves are sometimes appressed-puberulous or muricate. These variants may resemble A. ataxiphylla subsp. magna which is distinguished by its 5-merous flowers and acuminate bracteoles and calyx lobes. Petal striations are strongest on specimens from between Perth and Mount Barker. A variant with linear, uncinate, often muricate phyllodes 3–9 cm long and non-winged stems is scattered at a few locations from between Bindoon and New Norcia, near York and S to Mt Dale (e.g. 30 km S of York on Yarra Rd, R.J.Cumming 2771A & B, PERTH). Elsewhere the phyllodes are rarely muricate or uncinate and not reaching 9 cm in length. Stem wings are present except on some specimens from the Mingenew–Three Springs and Pingelly–Kojonup areas.
Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia
Minor edits by J.Rogers
B.R.Maslin
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