Family

Fabaceae

Distribution

Scattered distribution from Burakin (c. 55 km SE of Dalwallinu) S to near Lake Grace and E to near Mt Andrew (c. 90 km SW of Balladonia) and Coolgardie, south-western W.A.

Description

Prostrate domed or spreading shrub to 1 m high. Branches dividing into numerous, rigid, ascending to erect, ±spinescent, green or subglaucous, glabrous, ±ribless branchlets, rarely narrowly winged or flexuose. Phyllodes few at base of terminal branchlets, absent from the upper inflorescence-bearing nodes, lanceolate to narrowly oblong-elliptic, infrequently linear, mostly 1–2 cm long and 2–4 mm wide, green to subglaucous, glabrous; midrib obscure; lateral nerves absent. Inflorescences normally 1-headed rudimentary racemes with axes 0.5–1 mm long; peduncles (3–) 4–9 mm long, glabrous, recurved in fruit; heads globular, 4–5 mm diam., normally 20–30-flowered, golden; young buds light orange or red. Flowers 5-merous; sepals free. Pods mostly narrowly oblong, prominently rounded over seeds, to 4 cm long, mostly 4–6 mm wide, thinly chartaceous and very brittle, glabrous. Seeds normally transverse, ovate to elliptic, 3–4 mm long, dull, black, exarillate; funicle filiform.

Habitat

Grows in loam, clay loam, clay, sandy loam and sand, in open shrub mallee and woodland with various Eucalyptus species, on flat or gentle undulating plains.

Specimens

W.A.: 7.7 km E of Burakin towards Beacon, R.Cumming 2336 (PERTH); 9.5 km W of Bullabulling towards Southern Cross, R.Cumming 2484 (PERTH); 0.8 km N of Salmon Gums towards Norseman, B.R.Maslin 2443 (CANB, PERTH); 7 km N of Mt Andrew, c. 116 km SE of Norseman, K.Newbey 7776 (PERTH).

Notes

A variant from Westonia (e.g. C.A.Gardner 1850, NSW, PERTH) is unusual in that the branchlets are trifariously narrowly winged; other collections from other localities also show this condition but to a lesser extent. Another variant from between Kulin and Lake Grace (B.R.Maslin 4069, PERTH) is very unusual in its narrow pods (3 mm wide) with longitudinal seeds.

Sometimes confused with the more northerly distributed A. exocarpoides on account of its ±spinescent branchlets with few small phyllodes, but that species is a larger, coarser shrub with terete phyllodes, long, submoniliform, thinly coriaceous pods and arillate seeds. Acacia erinacea is another species with spinescent branchlets, few phyllodes and prostrate habit, but is not close to A. deficiens; it is a more intricately branched shrub with shorter, more pungent branchlets, smaller, differently shaped phyllodes, united sepals, usually crustaceous, narrowly to broadly oblong pods and arillate 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