Acacia sertiformis A.Cunn., Bot. Mag . 62: subt. 3394 (1835)
Open, sparsely branched shrub to 2 m high; branches arching downwards. Branchlets pruinose, sparsely or occasionally moderately hairy, rarely glabrous. Phyllodes widely spreading and rotated (20–) 45–90 from plane of branchlet, frequently convex, normally broadly elliptic to orbicular, (10–) 15–20 (– 25) mm long, (9–) 10–16 (–20) mm wide, l:w = (0.9–) 1.2 (–1.5), with asymmetrical and obliquely truncate or cordate base, margin undulate, with obtuse and obliquely uncinate apex, dull, grey-green and usually glaucous, glabrous except hairy on pulvinus, margin and midrib, sometimes lamina sparsely hairy; gland mostly 0–3 mm above pulvinus. Inflorescences with normally patent peduncles, (8– ) 12–16 (–20) mm long, sparsely pilose, occasionally glabrous; heads 9–10 (–11) mm diam., (25–) 30–60 (–75)-flowered, yellow to deep yellow. Corolla normally glabrous. Pods broadly oblong, straight or curved, 30–70 mm long, 12–17 mm wide, firmly coriaceous, normally pruinose; margin flat to undulate.
Occurring in eastern Australia from Barakula, Wallangarra, Warwick and Goombungee, Qld, and then from the southern end of the Pilliga scrub to Goulburn River valley and to north of Dubbo, N.S.W. Usually in Eucalyptus and Callitris woodlands on stony sandy loam soils.
The pruinose branches, together with the grey-green glaucous phyllodes that have obliquely truncate to shallowly cordate bases, readily distinguish this species from the other species of the ‘ A. uncinata group’. Characteristically, the habit is a few-branched, open, single-stemmed shrub with long arching branches with many, large, deep yellow flowers inserted along branchlets. Plants in the southern end of the distribution, from Ilford to Baerami and south to the Mellong Ra. and some Queensland specimens are clothed with sparse, long hairs (to 2 mm), and the phyllodes have a hirsute mucro to more than 2 mm long. The northern N.S.W. populations have phyllodes with smaller mucros (less than 2 mm long) and the hairs are much shorter. The young phyllodes are densely pubescent with grey to pale fawn-coloured hairs, becoming glabrous when mature. In some areas of the Hunter Valley A. sertiformis is sympatric with A. piligera , another member of the ‘ A. uncinata group’, and it is possible that the two may hybridize in places. See also A. clandullensis .
Type of accepted name
Liverpool plains, N.S.W., May 1825, A.Cunningham 99 ; lecto: K; isolecto: BM, K, fide B.J.Conn & T.Tame, Austral. Syst. Bot. 9: 839 (1996).
Synonymy
Acacia undulifolia A.Cunn. ex G.Don var. sertiformis (A.Cunn.) Benth., Fl. Austral . 2: 356 (1864). Type: as for accepted name.
Representative collections
Qld: 400 m along Mt Janet Rd, W of Baupaume, A.R.Bean 5871 & P.I.Forster (BRI). N.S.W.: Yass, without date, W.W.Froggatt s.n . (NSW371124); 5.5 km S of Putty, T.M.Tame 700 (NSW); N of Coonabarabran, T.M.Tame 2421 (NSW); 0.5 km along Mt Vincent Rd, 1 km S of Ilford, T.M.Tame 3987 (NSW).
(BJC &TMT)