Acacia omalophylla A.Cunn. ex Benth., London J. Bot. 1: 365 (1842)
Yarran
Tree 5–10 m high. Branchlets angular at extremities, sparsely appressed-puberulous or glabrous. Phyllodes narrowly elliptic-oblong, straight to slightly curved, 4–11 cm long, 4–9 mm wide, curved-acute, coriaceous, scurfy to glabrous, with numerous closely parallel, obscure nerves. Inflorescences 2- or 3-headed racemes; raceme axes 1–5 mm long; peduncles 2–6 mm long, sparsely to densely appressed-puberulous; heads globular, 4–5 mm diam., 20–30-flowered, golden; bracteoles oblong to obovate. Flowers 5-merous; sepals 1/3–2/3 united. Pods linear, slightly raised and irregularly constricted between seeds, straight to slightly curved, to 9 cm long, 3–5 mm wide, chartaceous or coriaceous, longitudinally nerved, glabrous; margins thickened. Seeds longitudinal, broadly elliptic, 3–5 mm long, dark brown; aril small, apical.
Widespread, occurring in central southern Qld S from between Yaraka and Duaringa; also occurring across the north and central western slopes and western and far western plains of central N.S.W., just crossing the Murray R. into Vic. Grows in Belah ( Casuarina cristata ) communities in brown soils with calcareous nodules, in Bimble Box ( Eucalyptus populnea ) open woodland in red earth and in various other soil and semi-arid vegetation types.
G.Bentham originally described this species as A. omalophylla , but in Fl. Austral. 2: 383 (1864) he corrected it to A. homalophylla , a more etymologically correct form. The conclusion reached by L.Pedley, Austrobaileya 1: 200 (1978), regarding the spelling of the name is adopted here.
Closely related to A. melvillei which has broader pods with transverse seeds, generally larger flower-heads and commonly broader phyllodes. These two species seem related to A. pendula which has densely appressed-puberulous phyllodes, pendulous branches and winged pods.
Type of accepted name
Lachlan R. and Liverpool Plains, N.S.W., May 1817, A.Cunningham 419 ; lecto: K, fide L.Pedley, Austrobaileya 1: 200 (1978); isolecto: BM.
Synonymy
Racosperma omalophyllum (A.Cunn. ex Benth.) Pedley, Austrobaileya 2: 353 (1987). Type: as for accepted name.
Illustrations
F. von Mueller, Iconogr. Austral. Acacia dec. 6 [pl. 7] (1887), as A. homalophylla ; L.F.Costermans, Native Trees & Shrubs SE Australia 326 (1981); G.M.Cunningham et al. , Pl. W New South Wales 363 (1981); M.Simmons, Acacias Australia 2: 141 (1988); T.Tame, Acacias SE Australia 82, fig. 70, pl. 70 (1992).
Representative collections
Qld: E of Adavale towards Charlesville, M.E.Ballingall 2164 (BRI, PERTH); Blue Bell Gully Ck, N of Springsure, B.O’Keeffe 855 (BRI, PERTH). N.S.W.: 25.7 km N of Cobar, N.T.Burbidge 6594 (PERTH). Vic.: c. 35 km NW of Wangaratta, J.Hawker for N.G. Walsh 2079 (PERTH).
(RSC & BRM)