Acacia exilis Maslin, Nuytsia 4: 87; 89, fig. 7 & 101, fig. 11 (1982)
Shrub or tree 3–6 m high; crown normally dense. Bark fibrous, grey. Branchlets terete, obscurely (non-resin) ribbed, glabrous. Phyllodes filiform, slightly curved to shallowly serpentinous, terete, 10–18 cm long, c. 1 mm diam., with normally delicately curved to uncinate tip, not rigid, pale subglaucous, glabrous except pulvinus puberulous adaxially at base, finely striate. Inflorescences simple, 2 per axil; peduncles 8–13 mm long, glabrous; spikes 10–20 mm long, subdensely flowered, light golden. Flowers 5-merous; sepals united into a sinuate-toothed cup, 1/4–1/3 length of petals, villous. Pods linear, constricted between and slightly raised over seeds, shallowly curved, to 9 cm long, 4–5 mm wide, firmly chartaceous, greyish brown, glabrous. Seeds longitudinal, oblong-elliptic to elliptic, 4–5 mm long, slightly shiny, brown; areole minute; aril terminal, whitish.
Confined to a restricted area of the Hamersley Ra. from Hamersley Stn SE to Coppin Pool, W.A. Grows on low rocky hills in iron-rich soils derived from Marra Mamba and Brockman Iron Formations, with several Acacia spp. and a ground cover of spinifex.
Most closely allied to A. tenuissima which has resin-ribbed branchlet apices, generally shorter phyllodes, shorter, paler yellow, more densely flowered spikes, narrower pods and yellow arils; moreover, A. tenuissima is commonly a shrub to about 2 m high. Sometimes sympatric with A. aneura which is distinguished by its grey-green phyllodes, more densely flowered spikes, free sepals and broader pods.
Type of accepted name
Hamersley Ra. Natl Park, 8.1 km from Milli Milli Springs towards Coppin Pool, W.A., 7 May 1980, M.Trudgen 2413 ; holo: PERTH; iso: CANB, K, MEL, NY.
B.R.Maslin, op. cit. 89, fig. 7.
W.A.: Tom Price, 0.8 km from minesite entrance, K.Atkins 1221 (CANB, K, PERTH); Hamersley Ra., E.M.Cole WA5097 (PERTH); 27 km from Tom Price on road to Paraburdoo, B.R.Maslin 4666 (BRI, CANB, K, MEL, NY, PERTH); Hamersley Ra. Natl Park, 1.4 km SW of hut at Coppin Pool, M.E.Trudgen 2548 (AD, BRI, NSW, PERTH).
(BRM & RSC)