Acacia auriculiformis A.Cunn. ex Benth., Lond. J. Bot. 1 (1842)

Latin for 'ear-shaped'.

Acacia auriculaeformis Benth. [Spelling variant]
Acacia moniliformis Griseb.
Racosperma auriculiforme (A.Cunn. ex Benth.) Pedley

Spreading tree to 28 m high, bole up to 12 m and 50 cm d.b.h. Bark grey or dark grey, deeply fissured in old specimens, hard; inner bark cream; sapwood deep cream, heartwood dark brown. Branchlets angular, glabrous. Phyllodes curved or falcate, acute or subacute, 10-16 by (1.2-)1.5-2(-3) cm, 4-8(-10) times as long as wide, glabrous, greyish green, major veins and margins not yellow, pulvinus 4-6 mm, with at the top a gland, swollen, c. 1 mm in diameter, with a narrow orifice; major prominent longitudinal veins 3 or 4, at the base running together towards the basiscopic margin or in the middle and with several crowded, somewhat anastomosing secondary veins. Spikes somewhat interrupted, 8(-10) by 0.6-0.7 cm, on glabrous peduncles, 0.5-0.8 cm, paired in the axils of the distal phyllodes. Flowers golden yellow, fragrant, pentamerous. Calyx 0.7-1 mm, glabrous; lobes triangular, 0.2 mm. Corolla 1.7-2 mm, glabrous; lobes reflexed, oblong, c. 1 mm. Stamens c. 3 mm. Ovary densely puberulous. Pod brown, often glaucous, flat, contorted, with undulate margins, c. 6.5 by 1-1 .5(-2.5) cm; valves subwoody, glabrous, veins transverse, anastomosing. Seeds black, transverse, elliptic, c. 5 by 3.5 mm; areole large and almost closed; funicle orange, 3.8-5 by 3-5.5 mm, completely encircling the seed.

Originally growing on savannas, woodlands, swamp edges, coastal savannas, grasslands, monsoon forests and regrowth up to 90 m altitude in Australia and New Guinea, introduced in western Malesia where it is consequently mainly found in plantations or secondary, open vegetation types. On sandy soils.

Wood used for wood-pulp. Poles used for house construction. Bark locally collected for tannins. In western Malesia often used as ornamental roadside tree.

Introduced in many places in western Malesia, but originally from northern Australia and New Guinea.

Observed to hybridize with Acacia mangium.