Acacia sibilans Maslin, Nuytsia 4: 402; 403, fig. 11, 405, fig. 12 & 408, fig. 14 (1983)
Silvery, speading tree 3–7 (- 12) m high; branches often slightly twisted and spreading horizontally. Bark fibrous, grey. Branchlets appressed-puberulous, glabrescent. Phyllodes ascending to erect, filiform, straight to shallowly curved to sinuous, terete, (8- ) 10–18 cm long, 0.8–1 mm diam., with curved to uncinate apex, not rigid, silvery appressed-puberulous early but hairs confined to between nerves with age, finely multistriate. Inflorescences 2- or 3-headed racemes; raceme axes 0.5–1.5 mm long; peduncles 5–12 mm long, silvery appressed-puberulous; heads globular, 5 mm diam., 26–28-flowered, golden. Flowers 5-merous; sepals free; petals pale yellow or silvery appressed-puberulous. Pods pendulous, moniliflorm, to 20 cm long, 7–10 mm wide, crustaceous, finely longitudinally nerved, hoary when young, ageing glabrescent except between seeds. Seeds longitudinal, compressed-elliptic, 9–12 mm long, dull, dark brown; aril small, pale yellow.
Scattered from Shark Bay inland to near Mileura Stn, also from Roy Hill, c. 500 km N of Mileura Stn, north-western W.A. Grows on plains and alluvial flats in shallow loam and sand over limestone, in low chenopodiaceous shrubland and, further inland, in Acacia shrubland.
Closely related to A. auripila . Also related to A. papyrocarpa , which has chartaceous, flat pods with smaller seeds, smaller flower-heads and generally shorter, straighter, subterete to flat phyllodes. Phyllodes sometimes resemble those of A. coriacea which is readily distinguished by its united sepals and large, bright orange seed arils.
Type of accepted name
29 miles [46.5 km] N of The Overlander [Roadhouse] (Denham turnoff), North West Coastal Hwy, W.A., 9 Sept. 1970, A.S.George 10360 ; holo: PERTH; iso: CANB, K, MEL, PERTH.
B.R.Maslin, op. cit . 403, fig. 11 & 405, fig. 12.
W.A.: 26.5 km N of Tropic of Capricorn beside North West Coastal Hwy, 28 Nov. 1983, W.Edgecombe (PERTH); c. 15 km S of Roy Hill Stn on Great Northern Hwy, B.R.Maslin 5271 (BRI, CANB, K, PERTH); Austin Downs Stn near Cue, A.A.Mitchell 902 (BRI, MEL, NY, PERTH).