WATTLE

Acacias of Australia

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Acacia pterocaulon Maslin

Family

Fabaceae

Distribution

Known only from within a range of hills W of Morawa, W.A.

Description

Intricate shrub to 1.3 m high. Branchlets glabrous. Phyllodes continuous with branchlets, bifariously decurrent and forming opposite wings with each one extending to the next below; wings 2-6 mm wide, coriaceous, subglaucous, glabrous, with marginal nerve prominent; free portion of phyllodes erect, lanceolate to narrowly triangular, straight or very shallowly incurved, 1–5.5 cm long, with main nerve central; gland basal. Inflorescences racemose; raceme axes 1–10 cm long, normally narrowly winged at anthesis; peduncles 10–15 (–20) mm long, glabrous; heads globular, 10–15 mm diam. at anthesis (dry), densely 60–70-flowered, golden. Flowers 5-merous; sepals ±free, linear-spathulate. Pods linear, to 12 cm long, 4–5 mm wide, coriaceous-crustaceous, ±pruinose, glabrous. Seeds longitudinal, oblong,
4.5–5 mm long; aril subconical.

Habitat

Grows in rocky (chert) clay loam on slopes of hills, in Eucalyptus woodland or dense casuarina scrub.

Specimens

W.A.: type locality, R.J.Cumming 2194 (MELU, NSW, PERTH).

Notes

Vegetatively resembling the more southerly distributed A. glaucoptera and some forms of A. willdenowiana but readily distinguished by its linear, ± straight pods which are 4–5 mm wide. Additionally, A. glaucoptera is recognised by its much smaller flower-heads, extremely reduced 1-headed racemes (to 0.5 mm long) and densely tomentulose phyllode axils. Acacia willdenowiana is further recognised by its rush-like growth habit, pale yellow to white heads with 13–21 flowers, united sepals and transverse seeds.

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