Family

Fabaceae

Distribution

Restricted to Cape Arid Natl Park and Middle Is. just off the coast, south-western W.A.

Description

Shrub 0.6–2 m high. Branchlets slightly angled apically, sparsely appressed-puberulous or glabrous. Stipules caducous, subulate, 1–1.5 mm long. Phyllodes ascending, narrowly oblanceolate, straight to slightly incurved, 1.5–3 cm long, 2–5 mm wide, obtuse, mucronulate, glabrous, 2-nerved per face; adaxial margin with 2 nerves for 1/4–1/2 length of phyllode; nerves coalescing near the gland. Inflorescences simple, 2 per axil; peduncles 6–13 mm long, glabrous; basal bract caducous, cucullate, rostriform, glabrous; heads globular, 3.5–4 mm diam., 20-flowered, golden; bracteoles spathulate. Flowers 5-merous; sepals free, spathulate. Pods linear, undulate, to 4.5 cm long, 4–4.5 mm wide, coriaceous, glabrous. Seeds longitudinal, widely elliptic, 3 mm long, dull, obscurely mottled brown; aril subterminal.

Habitat

Grows in association with granite among boulders and in granitic gravel.

Specimens

W.A.: Cape Arid, C.A.Gardner 12953 (PERTH); c. 1–2 km NNE of mouth of Thomas R., near Belinup Hill, A.S.Weston 7614 (AD, PERTH); Middle Is., A.S.Weston 8887 (PERTH).

Notes

A member of the ‘A. sulcata group’. Related to the more northerly distributed A. dura which normally has linear phyllodes with a single adaxial nerve and pods ±constricted between seeds. Acacia nitidula is perhaps nearest the compressed-phyllode element of A. sulcata var. platyphylla which has terete to compressed, shorter and narrower phyllodes. Also similar to some forms of A. mutabilis subsp. mutabilis which have quite regularly 5-nerved phyllodes, and larger, shiny, black seeds with a terminal, conical aril. Possibly related as well to A. deflexa and A. gemina.

FOA Reference

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

Author

Minor edits by J.Reid

R.S.Cowan