Common Name

Grass Wattle, Two-winged Acacia

Family

Fabaceae

Distribution

Sporadic from near Coorow S to near Stirling Ra. (Stirling Ra. is E of Cranbrook), south-western W.A.

Description

Erect shrub 0.3–0.6 m high with a rush-like habit, sometimes to 1 m high or stems scrambling. Stipules minute. Phyllodes continuous with branchlets, bifariously decurrent forming opposite wings with each one extending to the next below; wings 1–5 (-15) mm wide, grey-green to glaucous, glabrous, rarely hairy; free portion of phyllode 5–20 (–50) mm long, acute, with a nerve close to upper margin; gland absent. Inflorescences racemose; raceme axes 2–11 cm long, commonly narrowly winged, if wings expand the peduncles appear simple and axillary; peduncles twinned, 6–15 mm long, glabrous; heads globular, 13–21-flowered, white, cream or pale lemon yellow; buds normally acute to subacute. Flowers 5-merous; sepals united. Pods curved, flat, to 6 cm long, 10–15 mm wide, thinly crustaceous, normally glabrous; margins thick. Seeds transverse, ±oblong, 5–6 mm long, arillate.

Habitat

Grows in sand, loam and lateritic soils, often in winter wet depressions, usually in woodland.

Specimens

W.A.: Boonanarring Brook near Gingin, J.J.Alford 391 (PERTH); c. 64 km SW of Winchester on Coorow–Green Head road, 12 June 1974, C.Chapman (CANB, K, MEL, NSW, NY, PERTH); Cottesloe, 22 July 1897, R.Helms (PERTH); c. 30 km ENE of Mount Barker, 25 May 1983, P.Luscombe (K, PERTH); 16 km W of Harvey, B.R.Maslin 443 (MEL, PERTH).

Notes

Phyllode width and head colour somewhat variable (see B.R.Maslin, Nuytsia 10: 166 (1995), for discussion).

Related to A. applanata with which it is sometimes sympatric or parapatric. Acacia alata differs in having a central main nerve and the free portion of the phyllode having 1–3 glands. Phyllodes sometimes resembling those of A. pterocaulon.

FOA Reference

Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia

Author

B.R.Maslin

Minor edits by J.Rogers