Acacia dilatata Benth., Linnaea 26: 608 (1855)
Sprawling or compact, multistemmed shrub to 0.7 m high. Branchlets usually puberulous. Stipules 2–4 mm long, rigid, commonly spinose. Phyllodes dimidiate, with adaxial margin conspicuously rounded with its proximal edge frequently parallel to branchlet, normally 10–20 mm long, 7–10 (- 15) mm wide, slightly undulate, short- or long-acuminate, pungent, coriaceous, dark green or yellow-green, usually puberulous; midrib very close to abaxial margin; secondary nerves running into adaxial margin. Inflorescences simple; 1 per axil; peduncles 5–10 mm long, usually puberulous; heads globular to obloid, subdensely 15–25-flowered, golden. Flowers 5-merous; sepals shortly united, with lobes linear-triangular; petals striate. Pods curved, terete, to c. 5.5 cm long, 4–5.5 mm diam., crustaceous, dark red-brown, longitudinally striate, usually finely puberulous. Seeds longitudinal, oblong, 4.8–5.5 mm long, brown; aril terminal, conical.
Scattered in south-western W.A. from near Mingenew S to Mogumber, also c. 30 km W of Wongan Hills and near Darkin Swamp, c. 35 km SW of York. Grows in often lateritic or rocky sand, in heath or low shrubland with scattered Eucalyptus and Banksia . Flowers during summer.
Glabrous variants are uncommon and occur between Eneabba and Mogumber (e.g. A.S.George 8643 ).
Similar to A. phaeocalyx , especially in phyllode, petal and pod morphology. Acacia flabellifolia , which occurs within the range of A. dilatata , has similar phyllodes but is readily distinguished by its spinose branchlets, non-striate petals and coiled pods.
Type of accepted name
Swan R., W.A. J.Drummond s.n. ; holo: K; ?iso: NSW.
M.Simmons, Acacias Australia 63 (1981).
W.A.: c. 5.5 km W of Mogumber siding, A.S.George 8643 (CANB, K, PERTH); c. 6.4 km S of Marchagee, B.R.Maslin 1444 (PERTH); northern edge of Mortlake Ck, Wongan Hills, K.F.Kenneally 5399 (PERTH); near Darkin Swamp, 23 Jan. 1924, O.H.Sargent s.n . (PERTH).