Acacia setulifera Benth., Linnaea 26: 625 (1855)
Rounded, often procumbent, bushy or sparse, glabrous, resinous, shrub or subshrub to 0.5 (–1) m high. Branchlets apically angular but soon terete, with coarse, often minutely resin-crenulated ridges, finely lenticellate. Phyllodes patent, elliptic or ovate (upper margin sometimes slightly more convex than lower margin), often slightly curved and undulate, 0.3–0.6 (–0.9) cm long, 1.5–3 (–4) mm wide, coriaceous, with a straight to very oblique, bristle-like appendage at apex; nerves obscure or rarely midnerve and 2 or more lateral nerves scarcely conspicuous; gland minute, basal, to 1 mm above pulvinus. Peduncles mostly 5–11 mm long, 0.4–0.8 mm wide. Capitula 5–8 mm diam., (12–) 15–26-flowered, bright yellow; bracteoles with very attenuated lamina apex, usually almost as long as the spreading buds. Flowers 5-merous; calyx cupular, 0.6–1.1 mm long, dissected to 1/5, reddish papillose towards apex; corolla 1.7–2 (–2.2) mm long, dissected for c. 1/2. Pods erect, narrowly oblanceolate, straight-sided, 2.5–5 cm long, 4–6 mm wide, obliquely nerved; margins slightly thickened. Seeds oblique, narrowly oblong-elliptic, 3–4.5 mm long, brown; funicle-aril narrowly conical.
Occurs near the Carr Boyd Ra. (S of Kununurra) in the east Kimberley region of W.A., and in the Victoria River district, N.T. Grows mainly on sandstone ridges or escarpments, in eucalypt or Terminalia woodland. Flowers recorded Feb., Mar., May, Aug.
Acacia setulifera is most closely related to A. nuperrima , from which it differs by having smaller, more rounded phyllodes with a distinctly setose apical point. It is also characterised by long acuminate bracteoles prominent amongst the buds, persistent, ascending stipules and rather coarsely ribbed branchlets. There is a variant or possibly intergrades between these two species occurring in an area c. 10–43 km W of Timber Creek, N.T., which has a setose apical mucro on the phyllodes and acuminate bracteoles similar to A. setulifera , but with phyllodes to 1.2 cm long and slightly curved and sigmoid similar to, or approaching , A. nuperrima , e.g. I.B.Armitage 156 (NSW, PERTH), J.R.Maconochie 1125 (NSW, NT, PERTH), B.Maloney 25/75 (DNA, NSW, PERTH). A similar specimen occurs from further north at Tolmer Falls, Wangi Stn, T.S.Henshall 1829 (NT, PERTH).
Type of accepted name
NW coast of Australia [probably Holdfast Reach on the Victoria R., N.T., Nov. 1839, fide B.R.Maslin & A.S.Weston, W. Austral. Naturalist 19: 243–246 (1993)], [B.]Bynoe ; holo: K; iso: BM, NSW.
B.R.Maslin & A.S.Weston, loc. cit ., figs 1–3.
W.A.: c. 50 km SSW of Kununurra, A.S.Weston 900815-1 (MEL, NSW, PERTH) and A.S.Weston 900512-1 (PERTH). N.T.: Spirit Hills Conservation area, I.Cowie 7151 (DNA, NSW, PERTH); Victoria R. area, G.J.Leach 8204 & C.R.Dunlop (DNA, PERTH).