WATTLE

Acacias of Australia

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Acacia humifusa A.Cunn. ex Benth.

Family

Fabaceae

Distribution

Occurs in the Kimberleys, W.A., on the offshore islands in the Gulf of Carpentaria and on the N.T. mainland N of 16ºS, and from Cape York to Cape Cleveland, Qld, along the east coast and offshore islands, Qld.

Description

Shrub to 3 m high, to 6 m wide, spreading, sometimes almost prostrate or arborescent to 6 m, resinous. Bark fissured or rarely smooth, grey or brownish grey. Branchlets ±terete, light fawn to dark brown, velvety, tomentose or hirsute. Phyllodes asymmetrical, obliquely ovate-rhomboid to suborbicular, (2.5–) 4–8 cm long, (1.5–) 20– 40 (–60) mm wide, sometimes with a setose point at apex, coriaceous, ±tomentose mainly along nerves and margins, with 3 or rarely 2 or 4 prominent curved nerves joining the upper margin at different slightly indented points with lowest nerve concurrent with lower margin for several mm and terminating at or just below apiculate phyllode apex; minor nerves strongly reticulate; gland 1, basal, prominent. Spikes 1–3 cm long, golden. Flowers 5- or 6-merous; calyx 0.7–2 mm long, dissected to 1/3–1/2, hirsute, sometimes glabrous near base; ovary densely pubescent. Pods linear, slightly constricted between and raised over seeds, often curved, 3.7–7.5 cm long, 3–5 mm wide, crustaceous, velvety-hairy, breaking into 1-seeded portions. Seeds longitudinal, broadly oblong-to narrowly oblong-elliptic, 4.3–6 cm long, blackish brown; areole open, elongate, depressed.

Phenology

Flowers Feb.–Sept.

Habitat

Grows in sand, in heath, low Acacia woodland and along the sea shore, on hillsides or above gorges on shallow rocky soil in eucalypt woodland, in sandstone, granite or quartzite.

Specimens

W.A.: Mt Broome, W.V.Fitzgerald 833 (NSW). N.T.: Wessel Is., P.K.Latz 3343 (DNA, NSW); Magela Ck, M.Lazarides 9175 (CANB, NSW); 20 km NW of Bauhinia Downs Stn, G.Leach 563 (DNA, NSW). Qld: 42.2 km WNW of Lakeland Downs, R.G.Coveny 6993 & P.Hind (BRI, CANB, K, MEL, NSW, QRS, US); 30 km N of Mt Surprise turnoff, A.N.Rodd 4485 & M.Hardie (B, BRI, MEL, MO, NSW, RSA).

Notes

Sometimes confused with A. dimidiata which has ±glabrous corollas, inconspicuous bracteoles and longer spikes.

FOA Reference

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

Author

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

Dr M.D.Tindale and Dr P.G.Kodela with the assistance of M.Bedward, S.J.Davies, C.Herscovitch, D.A.Keith and/or D.A.Morrison