Acacia triptycha F.Muell. ex Benth., Fl. Austral. 2: 337 (1864)
Bushy shrub to small tree 1–4 m high. Branchlets glabrous. New growth golden appressed-puberulous. Phyllodes ascending to erect, linear, straight or more often shallowly curved, flat to subterete, (3- ) 7–10 (- 13) cm long, 1–2 mm wide, arcuately long-acuminate with point appressed-puberulous ageing glabrous, glabrous (except tip), 8-nerved in all, 3-nerved per face when flat; gland 1–11 (–15) mm above pulvinus. Inflorescences simple, 2 per axil; peduncles 4–10 mm long, glabrous to sparsely appressed-puberulous; heads globular, 4–6 mm diam., mostly 26–40-flowered, golden. Flowers 5-merous; sepals free, spathulate; petals partly united. Pods linear, slightly raised over seeds, straight, to 6 cm long, 3–4 mm wide, thinly crustaceous, glabrous to sparsely appressed-puberulous. Seeds longitudinal, elliptic to oblong-elliptic, 2.8–3.3 mm long, glossy, mottled shades of brown, nigrescent; aril subapical.
Occurs sporadically from Mt Frankland E to near Ponier Rock and Cape Arid Natl Park in south-western W.A. Grows usually in association with granite or quartzite in granitic sand or reddish-brown clay-sand over quartz, in open scrub or heath on hills, hence the sporadic distribution.
The J.Drummond 4: 132 and 5: 5 collections cited by G.Bentham, Fl. Austral. 2: 337 (1864), under this name are A. subflexuosa .
The closest relative is A. heteroclita which has broader phyllodes. Also related to A. trinalis and to the ‘ A. fragilis group’, particularly A. assimilis , which has slender, more nearly terete phyllodes with more numerous, less conspicuous main nerves.
Type of accepted name
Kalgan R., W.A., A.F.Oldfield s.n. ; lecto: MEL, fide R.S.Cowan & B.R.Maslin, Nuytsia 12: 445 (1999); isolecto: K, PERTH; paralecto: Termination Rock, [W.A.], G.Maxwell ; paralecto: K, MEL, PERTH.
F. von Mueller, Iconogr. Austral. Acacia dec. 2 [pl. 6] (1887).
W.A.: Mt Ragged, T.E.H.Aplin 4331 (AD, BRI, CANB, K, PERTH); Jacup Ck, Fitzgerald R., 12 Oct. 1935, C.A.Gardner s.n. (BM, PERTH); c. 10 km from Ravensthorpe towards Lake King, B.R.Maslin 3873 (CANB, G, K, MEL, NSW, NY, PERTH); 31 km W of Ponier Rock, K.Newbey 7626 (PERTH).