Prickly Acacia (Acacia nilotica)
Distinctive seedpods of prickly acacia
Prickly acacia is declared a Class A (to be eradicated) and Class C (not to be introduced to the NT) weed in accordance with the NT Weeds Management Act 2001. Prickly acacia is also a Weed of National Significance.
- Prickly acacia Photo Identification Table (pdf 144Kb)
Prickly acacia, is native to the tropics and subtropics of Africa through to Pakistan, India and Burma. It was deliberately imported into Australia as a shade and fodder tree prior to the 1960’s. Prickly acacia prospers along watercourses and can rapidly out-compete native plants for available water. It now threatens agricultural production and environmental values across more than 6.6 million hectares of Australia.
Once established along water courses and bore drains, prickly acacia can spread out onto adjacent grasslands. Thickets exclude native plants and animals, impacting ecological integrity and biodiversity. From an economic perspective, the thickets impede mustering, movement of stock and cattle access to water.
Prickly acacia prolifically produces seeds that can remain viable for in excess of 7 years. Cattle are the major contributors to seed spread, as they preferentially graze the high protein seed pods, then excrete the viable seeds. Seeds can also be transported on pelage and hooves. Any flowing water will also facilitate seed distribution.
Most of northern Australia is susceptible to prickly acacia invasion, including ecologically and economically important areas of the NT, including the Barkly Tablelands. In the NT prickly acacia only occurs as scattered, isolated infestations. Relatively low level infestations occur on a number of properties on the Barkly Tablelands and isolated incursions of prickly acacia are also present in the Katherine region. Outbreaks have occurred in Adelaide River and Batchelor, however these have been successfully eradicated.
Prickly acacia leaves and immature flowers
