Acacias of Australia

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Acacia triquetra Benth.




Occurs in S.A. on the Eyre Peninsula from near Calca to Port Lincoln, Yorke Peninsula S of Port Rickaby and on Kangaroo Is.


Spreading glabrous shrub to 1.5 m high. Branchlets acutely angled towards apices, ribbed below phyllode insertion. Phyllodes on obvious stem-projections, patent to erect but commonly inclined to ascending, narrowly oblong to oblanceolate or narrowly elliptic, rarely linear, straight or slightly curved, usually (6–) 10–25 (–28) mm long and 2–6 mm wide, l:w = 3–8, ±rounded-obtuse and excentrically rostellate, dark green; midrib not prominent; lateral nerves absent or obscure; gland adjacent to apical mucro; rarely a few phyllodes with an additional gland near middle. Inflorescences rudimentary 1-headed racemes with axes 0.5–1.5 mm long, 1–2 per node; peduncles 3–8 (–11) mm long, slender; heads globular, 10–18-flowered, golden. Flowers 5-merous; sepals free. Pods linear, straight to shallowly curved, to 6 cm long, 3–4 mm wide, firmly chartaceous. Seeds ±longitudinal, normally oblong, 2.5–3.5 mm long, slightly ridged peripherally, subnitid, dark brown; aril subterminal.


Grows in coastal sand and limestone, sometimes on sea cliffs or in swampy scrub and in mallee association.


S.A.: c. 3 km N of Elliston, N.N.Donner 2430 (AD); c. 8 km SE of Bascombe Well HS, Eyre Peninsula, E.N.S.Jackson 1165 (PERTH); Formby Bay road area, southern Yorke Peninsula, 15 Sept. 1962, M.J.Hancock s.n. (AD); Bay of Shoals, Kangaroo Is., J.C.Noble 624 (AD).


A member of the ‘A. microcarpa group’ (see B.R.Maslin, Nuytsia 6: 39, 1987) and formerly confounded with A. acinacea. Putative hybrids between A. triquetra and A. microcarpa occur on the Eyre Peninsula; also putatively hybridizes with A. paradoxa.

A variant from Kangaroo Is. has unusually elongate phyllodes (23–38 mm long, 2–4 mm wide); typical A. triquetra also occurs on the Island.

Erroneously considered a Western Australian species by G. Bentham, Fl. Austral. 2: 354 (1864). The two Drummond specimens cited by Bentham under A. triquetra are A. meisneri.

FOA Reference

Data derived from Flora of Australia Volumes 11A (2001), 11B (2001) and 12 (1998), products of ABRS, ©Commonwealth of Australia


Minor edits by B.R.Maslin & J.Rogers