Common Name

Koolanooka Delicate Wattle

Family

Fabaceae

Distribution

Restricted to E of Morawa, south-western W.A.; known from two localities, Koolanooka Hills and 10 km to the SE at Perenjori Hills.

Description

Openly branched, spreading shrub 1–2 m high, stems slender and ±contorted. Branchlets finely appressed-puberulous at extremities, glabrescent. Phyllodes inserted on raised stem projections, shallowly to moderately recurved, terete but drying subterete to compressed, 7–25 mm long, 0.7–1 mm wide, gradually or ±abruptly narrowed to a straight, pungent tip, rigid, glabrous or pulvinus often hairy adaxially; with 9 or 10 distant longitudinal nerves, 3-nerved per face when compressed; stomata evident between nerves at x10 mag.; gland 1 (–2); pulvinus slightly basally flared. Inflorescences simple, 1 or 2 per axil; peduncles 3–5 mm long, to 9 mm in fruit, glabrous, the caducous basal bract cucullate and obtuse; heads globular, small (3–4 mm diam. when dry), 11–18-flowered, light golden. Flowers 5-merous; sepals ±free. Pods narrowly oblong to linear, moderately to strongly curved, sometimes open circled or coiled, 3.5–6.5 cm long, 3–3.5 mm wide, firmly chartaceous, curved (sometimes into an open circle or coil), ±glabrous. Seed (1 only) longitudinal, oblong elliptic, 3 mm long, glossy, dark brown; aril white.

Phenology

Flowers Aug.–Oct.

Habitat

Grows in clay-loam on slopes and crests of low banded ironstone and laterised banded ironstone hills in woodland and mallee shrubland.

Specimens

W.A.: Koolanooka Hills [precise localities withheld for conservation purposes], B.R.Maslin 9100 (CANB, K, MEL, NSW, NY, PERTH) and R.Meissner & Y.Caruso 52 (PERTH); Perenjori Hills, S.Kern & A.Harris 12064 (PERTH).

Notes

A member of the ‘A. densiflora group’ related most closely to A. dissona and A. mackeyana which differ most obviously in having phyllodes with more numerous nerves and branchlets densely hairy. Additionally, A. mackeyana has thicker phyllodes with raised stomata and generally narrower, more thickly textured pods, and A. dissona has straighter, generally longer phyllodes and narrower pods. More distantly related to A. declinata from the south coast which differs most obviously in having wide-spreading to slightly retrorse branchlet hairs, 7- or 8-nerved phyllodes and undulate pods.

FOA Reference

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

Author

J.Reid, B.R.Maslin