Wilson's Wattle  |  

Acacia wilsonii

Status: Endangered on the EPBC Act list

A prostrate shrub, normally 0.2−0.3 m tall, to c. 0.3 m wide, the branches spreading horizontally. Branchlets at first slightly angled, densely villous to pubescent with minute black resin hairs intermixed, soon terete and glabrous except resin hairs sometimes persistent. Stipules triangular, acuminate, 1.5−3 mm long, persistent. Phyllodes sessile, continuous on branchlets and not easily detached from them, terete to subterete, 6.5−22.5 cm long, 1−1.5 mm diam., coriaceous to semirigid, ascending to erect, shallowly incurved to shallowly sigmoid or sinuous, glabrous, green (ageing yellow-green), stomata evident at x10 mag.; apex acute, commonly slightly curved to uncinate, innocuous; longitudinal nerves 8, strongly raised when dry (nerves separated by well-defined, longitudinal furrows). Gland absent. Inflorescences simple, 1 or 2 per axil; peduncles 4−10 mm long, sometimes to 14 mm long in fruit, densely villous and with minute resin hairs intermixed; basal peduncular bract lanceolate, 2.5 mm long, persistent. Heads globular, golden, 8 mm diam., densely 24−37-flowered; bracteoles exserted in young bud. Flowers 5-merous; sepals 1/2−3/4 as long as petals, narrowly elliptic, 1/2−3/4 –united, ciliolate; petals ½-united, elliptic, glabrous. Pods linear, subterete, not constricted between seeds, 3−5.5 cm long, 3−3.5 mm wide, thinly crustaceous, slightly curved, dotted with minute, black resin hairs, greenish grey with yellowish, non-thickened margins. Seeds longitudinal, obloid, 2−3 mm long, 1.5 mm wide, 1.5 mm thick, dull, brown, tuberculate, tubercules irregular in form, the areole area smooth, paler, sometimes raised; pleurogram U-shaped to nearly semicircular; aril terminal, yellow, scalloped.

Government evidence of impact of climate change:

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  • Australian Government, Conservation Advice, Acacia wilsonii

    Climate change modelling for the south west predicts a decline in rainfall; and some seasonal shift to summer rainfall events; which is likely to increase the potential impact of drought on the species.

    Past; current and future Altered fire regimes Whole population Severe It is not certain how the species responds to fire but it is likely to be killed by fire and regenerate from seed.

    If fire frequency is increased the soil seed bank could be depleted before juvenile plants have reached maturity.