Family

Fabaceae

Distribution

Discontinuous, occurring from near Mingenew SE to near Three Springs, also from near Watheroo (c. 100 km due S of Three Springs) SSE to near Tammin, also occurring at the Chiddarcooping Nature Reserve (c. 260 km due E of Watheroo), south-western W.A.

Description

Much-branched ±spreading shrub 0.2–0.6 m high. Branchlets ±slender, ±straight, patent to erect, often spinescent, hirsutellous to hirtellous, with hairs sometimes stellate. Phyllodes inequilaterally obtriangular, with upper margin forming a prominent rounded angle and lower margin shallowly convex, 2–5 mm long, 1.5–4 mm wide, ending in a short mucronate or sometimes ±pungent point, slightly thickened, ±hirsutellous to hirtellous, ±obscurely 1- or 2-nerved with main nerve near abaxial margin. Inflorescences rudimentary 1-headed racemes with axes > 0.5 mm long; peduncles 2–5 mm long, sparsely to moderately hirsutellous to hirtellous; basal bracts 2, persistent; heads globular, 3–4 mm diam., 10–17-flowered, golden. Flowers 5-merous; sepals 1/3–2/3-united, 1/4–1/3 length of petals; petals nerveless, glabrous. Pods closely coiled, to c. 8 mm long (unexpanded), 2–2.5 mm wide, firmly chartaceous to thinly coriaceous, red-brown, glabrous or hirtellous. Seeds longitudinal, 2–3 mm long, brown mottled black; aril oblique, thick.

Habitat

Grows in often stony or lateritic loam, sometimes in sand, in Melaleuca heath and eucalypt woodland, on low rocky hills.

Specimens

W.A.: Swan R., J.Drummond s.n. (K) and 158 (BM, G, K, LUND, MEL, OXF, P); 11 km N of Three Springs on The Midlands Rd, B.R.Maslin 5489 (CANB, PERTH); Chiddarcooping Nature Reserve, B.R.Maslin 6386 (PERTH, Z); 3.2 km S of Tammin, K.Newbey 1951 (PERTH).

Notes

Specimens from Yerecoin–Walebing area (near New Norcia) are unusual in their seemingly stellate branchlet and phyllode indumentum (hairs simple elsewhere). Phyllodes are slightly smaller on specimens in the east of the range compared with those from the west, fide B.R.Maslin, Nuytsia 12: 343–344 (1999).

Formerly confused with A. bidentata which has non-spinescent, scurfy-white branchlets, creamy white to pale yellow heads, arcuate to 1 1/2-coiled pods and non-mottled seeds. Similar to broad phyllode forms of A. acanthoclada which has glabrous peduncles and 1-nerved petals. Also similar to W.A. forms of A. pravifolia which is distinguished by its normally glabrous peduncles and non-mottled 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