Prickly Acacia

Acacia nilotica
Family: Mimosaceae

Growth Habit: Prickly acacia originated from Pakistan. This weed can grow up 10 metres in height but averages 4-5 metres. It has an umbrella appearance and was cultivated here to provide shelter and fodder for livestock. The plants are distinct with fern-like leaves, a pair of stout thorns (1-5cm long) and pods. Mature plants are usually single stemmed while younger plants form dense thorny thickets.

Type of Plant: Prickly acacia is a thorny shrub or small tree.

Flowers: The ball-shaped flowers are golden-yellow in colour and are about 1cm across. The flowers grow in a group of 2 to 6 on a stem.

Fruit/Seed: The flat pods are 10-15 cm in length go grey when ripe. The pods contain the seeds.

Dispersal: Dispersed by seed.

Distribution: Found throughout Queensland, major infested areas occurring from Barcaldine north to Hughenden and west to Longreach, Winton and Julia Creek. Also located along the New South Wales and Northern Territory borders. Millions of hectares of the Mitchell grass plains have been infested.

Status: Prickly acacia is a Weed of National Significance.

Weed Impact:

  • Restricts access by stock
  • Interferes with mustering
  • Causes soil degradation
  • Pasture decreases as infestations increase
  • Increases the cost of maintaining bores
  • Absorbs water which is for stock or pasture

Information referenced from “Queensland Government, Department of Natural Resources Pest Fact No PP9.”