National recovery plan for the Downy Wattle (Acacia pubescens)

NSW National Parks and Wildlife Service
Environment Australia, February 2003
ISBN 0 7313 6504 6

4. Description

4.1 Scientific Description

The following description of A. pubescens is taken from Kodela & Harden (in press). A. pubescens (Vent.) R. Br. (family Fabaceae, subfamily Mimosoideae), is a spreading to slightly weeping shrub 1-5 m high; bark smooth, brownish grey; branchlets angled at apex becoming ± terete with ridges, hairy with long fine hairs. Leaves ± sessile on pulvinus, rachis (ie. the axis) 1.5-6.5 cm long, hairy, glands absent or small, often inconspicuous, jugary or rarely interjugary glands (ie. glands along the axis) irregularly present; pinnae (ie. leaflets) 3-12 pairs, 0.5-2.5 cm long; pinnules (the smallest leaflet segment) 5-20 pairs, mostly oblong to narrowly oblong, 1.5-5 mm long, 0.4-1 mm wide, glabrous. Inflorescences 6-49 in an axillary or terminal raceme with axis 2.5-11 cm long (axis often zigzagged) or sometimes in a terminal panicle; peduncles 2-6 mm long, glabrous or sparsely hairy; heads globose, 8-16-flowered, 3-6 mm diam., bright yellow. Pods ± straight, ± flat, ± straight-sided to variably constricted between seeds, 1.5-8 cm long, 4-6.5 mm wide, firmly papery to thinly leathery, glabrous, ± pruinose; seeds longitudinal; funicle filiform. Flowers August-October.

4.2 Distinguishing Features

Acacia pubescens can be distinguished from the other bipinnate Acacia species in the region by its conspicuously hairy branchlets and spreading hairs. The species has been known to hybridise with other bipinnate wattles. The National Herbarium of NSW has hybrid specimens of A. pubescens x A. baileyana (Cootamundra Wattle) and A. pubescens x A. jonesii. It is also known to hybridise with A. cardiophylla (S.R. Douglas, consultant, pers. comm.). The hybrids of A. pubescens x A. baileyana are noticeable by their foliage, which is bluer than the characteristic A. pubescens foliage (S. Burke NPWS pers. obs.). The hybrids are also less hairy and have more jugary glands (T. James, consultant pers. comm.).