Family

Fabaceae

Distribution

Occurs from near Stirling Ra. E to Israelite Bay, south-western W.A.

Description

Shrub usually 0.4–1 m high. Branchlets ribbed, glabrous. Stipules caducous. Phyllodes often subdistant, ascending to erect, usually shallowly incurved, acutely pentagonous in section by 5 prominently raised nerves (sulcate in between), if flat (mainly juvenile plants) the 2 adaxial nerves forming a broad upper margin, 2–4.5 cm long, usually 1–1.5 mm wide, ±epulvinate, glabrous; mucro often coarsely pungent; gland 3–7 mm above base. Inflorescences 1–3-headed racemes; raceme axes 1–5 mm long, glabrous; peduncles 4–8 (–10) mm long, glabrous; heads globular, 4.5–5 mm diam., 12–21-flowered, cream to pale yellow. Flowers 5-merous; sepals free. Pods linear, rounded over seeds, shallowly constricted or not between seeds, to 8 cm long, 3–4 mm wide, thinly coriaceous, dark red-brown, glabrous. Seeds longitudinal, oblong to elliptic, 3–4 mm long, shiny, black; aril thick.

Habitat

Grows in sand, lateritic gravel over white sand, quartzite granite-clay, in heath, mallee scrub and eucalypt woodland, on flat plains.

Specimens

W.A.: 18.5 km W of Scaddan, B.R.Maslin 2525 (CANB, K, PERTH); 16 km W of Israelite Bay Telegraph Stn, R.A.Saffrey 1344 (AD, NY, PERTH).

Notes

Close to A. pachyphylla. Phyllodes superficially similar to A. dura which has thick, compressed, 6-nerved phyllodes with a distinct pulvinus, smaller flower-heads in axillary pairs and a clavate aril on the seeds. Also reminiscent of A. mutabilis subsp. angustifolia which has distinctly pulvinate phyllodes, golden flower-heads and slightly narrower, black pods; A. longispinea also has pentagonal phyllodes which are much longer.

F.J.H. von Mueller’s A. gonophylla illustrations in Iconogr. Austral. Acacia dec. 2 [pl. 9] (1887) are unusual. The flowering branch shows dimorphic foliage characteristic of A. pachyphylla; the inflorescences are of A. gonophylla. The pods are A. gonophylla but persistent stipules are anomalous.

G.Bentham in Fl. Austral. 2: 340 (1864) referred to depauperate specimens from ‘Kojonerup range’ and ‘Phillips range’. I have not seen either collection but Bentham’s description of the stipules in the former suggests that it is A. pachyphylla (syn. A. gonophylla var. crassifolia).

Wind-pruned plants in Fitzgerald R. Natl Park are 0.15–0.3 m high with phyllodes to 3 mm wide.

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