Acacias of Australia

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Acacia demissa R.S.Cowan & Maslin

Common Name

Ashburton Willow, Moondyne Tree




Occurs in a restricted area inland from Shark Bay, bounded by Gifford Creek Stn (c. 270 km NE of Carnarvon), Byro Stn (c. 270 km SE of Carnarvon) and Belele Stn (c. 50 km NW of Meekatharra), W.A.


Shrub or tree to 4 m high, weeping. Branchlets pendulous, slender, glabrous. Phyllodes pendulous, linear to linear-elliptic or narrowly elliptic, (5–) 6.5–15 (–18) cm long, (1–) 1.5–4 (–6) mm wide, acute to acuminate with a curved to uncinate apex, thinly coriaceous, slightly shiny, olive green, glabrous, with numerous obscure closely parallel nerves, with marginal nerves commonly red or brown and (at least on young phyllodes) resinous. Inflorescences simple, 2 or 3 per axil; peduncles 2.5–5 mm long, normally glabrous; heads obloid to cylindrical, 8–23 mm long, subdensely flowered, golden; bracteoles spathulate. Flowers 5-merous, resinous; sepals united only basally, ciliolate. Pods oblong to narrowly oblong, to 10 cm long, 8–17 mm wide, thick and woody, commonly glabrous and slightly resinous; margins 2 mm wide, unwinged, yellowish. Seeds longitudinal, broadly elliptic to nearly circular, 6.5–9 mm long, dull, brown to black, minutely and irregularly pitted except areolar area; aril terminal, small.


Grows in a variety of habitats: low quartzite or granite hills, red-brown clay or loam on flats with mulga, on floodplains or in clayey sand along seasonally dry streams.


W.A.: floodplain of Murchison R., near Beringarra, C.A.Gardner 14487 (PERTH); 41 km from Byro Stn on track to Milly Milly Stn, B.R.Maslin 5177 (BRI, NSW, PERTH); Cobra Stn, 78 km N of Landor HS on track to Mt Augustus Stn, B.R.Maslin 5194 (CANB, K, MEL, PERTH); Belele Stn, A.A.Mitchell 799 (PERTH); 20 km S of Koonmarra HS, A.A.Mitchell 1174 (MEL, PERTH).


Related to A. quadrimarginea which is normally readily distinguished by its non-pendulous branchlets, characteristically spreading phyllodes and prominently winged pods. The two species are sympatric on Cobra Stn and there is some indication that intermediates may occur between them (e.g. A.A.Mitchell 1174, PERTH; B.R.Maslin 5022, 5208 & 5208a, all PERTH), fide R.S.Cowan & B.R.Maslin, Nuytsia 10: 27 (1995). Specimens from Koonmarra Stn have the shortest phyllodes known for the species.

FOA Reference

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

R.S.Cowan, B.R.Maslin