Acacias of Australia

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Acacia complanata A.Cunn. ex Benth.

Common Name

Flat-stemmed Wattle




Widespread, occurring in south-eastern Qld from the Jericho area E to Bundaberg, also SE to N.S.W. on the Dumaresq R. and northern coastal parts S to Coffs Harbour with a disjunct occurrence in the Torrington district.


Shrub or tree to 5 m high, branches arching downwards. Branchlets ±flexuose, flattened, narrowly winged, glabrous. Phyllodes often patent, narrowly elliptic, mostly 5–10 (–12.5) cm long and 10–30 (–45) mm wide, obtuse to subacute, thinly coriaceous, glabrous, with 7–9 prominent distant main nerves and openly reticulate in between; pulvinus 2–3 mm long. Inflorescences 4–8 per axil in axillary fascicle or sometimes fascicles racemose on axis to 30 mm long; peduncles 8–12 mm long, glabrous; heads globular, ±6 mm diam., 35–45 (–60)-flowered, bright yellow. Flowers 5-merous; sepals free to 1/2-united. Pods linear, rounded over seeds alternately on each side and shallowly to moderately constricted between them, to 15 cm long, 6–10 mm wide, thinly coriaceous-crustaceous, wrinkled ±reticulately over seeds, glabrous. Seeds longitudinal, subglobular, 4–5 mm long, dull, dark brown; funicle encircling seed.


Grows in sand, gravel and loam, usually over sandstone, in dry sclerophyll forest and heath.


Qld: c. 25 km S of Springsure on road to Rolleston, B.O’Keeffe 850 (PERTH). N.S.W.: 17.7 km NE of Maclean, J.O’Hara & R.Coveny 3511 (NSW, PERTH).


The markedly flattened branchlets and seeds with an encircling funicle serve to relate A. complanata to A. homaloclada; these characters distinguish these species from related taxa such as A. simsii and A. multisiliqua (which have narrower phyllodes). Acacia complanata is also similar to A. fleckeri.

FOA Reference

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


R.S.Cowan, B.R.Maslin

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