Acacia williamsonii Court, Muelleria 2: 163 (1972)
Whirrakee Wattle
Bushy shrub to 2 m high. Branchlets glabrous. Phyllodes narrowly linear, normally shallowly incurved, 4–9 cm long, usually 1.5–3 mm wide, narrowed at base, not rigid, glaucous and inclined to ascending, often green or subglaucous and patent at ends of flowering branchlets, glabrous; midrib not prominent; lateral nerves absent; gland 7–27 mm above pulvinus, often absent. Inflorescences racemose; racemes usually 1–3 cm long, glabrous, normally drying dark reddish brown; peduncles 2–3 mm long, rather stout, glabrous, sometimes appressed-puberulous, drying dark reddish brown to blackish; heads globular, subdensely 15–20-flowered, bright golden; bracteole laminae circular, dark brown to blackish, white-fimbriolate. Flowers 5-merous; sepals c. 5/6-united. Pods normally moniliform, to 9 cm long, 3–3.5 mm wide, firmly chartaceous to somewhat crustaceous, black, glabrous. Seeds longitudinal, oblong to elliptic, 3.5–4 mm long, somewhat shiny, black; aril clavate.
Occurs from Inglewood E to Rushworth, Vic.; it is especially common in the Bendigo ‘Whipstick’ where it grows in stony gravel or clay loam, in open Eucalyptus forest and Mallee open scrub. A specimen collected from a rocky outcrop on Curraweena Stn, 88 km N of Cobar, N.S.W. ( W.E.Mulham W478 , NSW), is assumed to have been introduced to the area.
A variant from near Rushworth, c. 50 km E of Bendigo (e.g. 4 Sept. 1974, J.H. Willis , MEL) differs especially in its very long racemes (to 9 cm long), and its linear pods (few seen) which are only slightly constricted between the seeds.
Closely allied to the less floriferous A. hakeoides which differs especially in its wider, green phyllodes, usually 20–27-flowered heads and 4–6 mm wide pods with dull seeds 5–7 mm long. Its flowers and bracteoles are similar to those of A. hamiltoniana .
Putative hybrids between A. pycnantha and A. williamsonii occur in the Bendigo ‘Whipstick’, and superficially resemble A. hakeoides .
Very decorative shrubs with a neat rounded or obconic shape and a profusion of bright golden inflorescences in the upper axils; admirably suited as an ornamental.
Type of accepted name
Bendigo, Vic., 14 Sept. 1923, D.J.Paton ; lecto: MEL, fide J.H.Willis, Victorian Naturalist 73: 156 (1957); isolecto: MEL.
Synonymy
Acacia williamsonii is based on the following: Acacia ligulata var. angustifolia H.B.Will., in A.J.Ewart, Fl. Victoria 1931: 594 (1931); A. hakeoides var. angustifolia (H.B.Will.) J.H.Willis, Victorian Naturalist 73: 156 (1957). as for accepted name.
Illustrations
G.R.Cochrane et al. , Fl. & Pl. Victoria 107 (1968); L.F.Costermans, Native Trees & Shrubs SE Australia 315 (1981); R.W.Elliot & D.L.Jones, Encycl. Austral. Pl . 2: 131 (1982); T.Tame, Acacias SE Australia 158, fig. 174, pl. 174 (1992).
Representative collections
Vic.: Bendigo Whipstick, c. 12 km due N of Bendigo township, B.R.Maslin 5848 (PERTH); Whipstick, 0.8 km N of Eaglehawk Rifle Ra., 23 Aug. 1959, W.Perry (MEL); Inglewood, J.Stuwe 825 (MEL).
(BRM)
The information presented here originally appeared on the WATTLE CD-ROM which was jointly published by the Australian Biological Resources Study, Canberra, and the Department of Parks and Wildlife, Perth; it was produced by CSIRO Publishing from where it is available for purchase. The WATTLE custodians are thanked for allowing us to post this information here.
