Rooikrans (Acacia cyclops): Recognising Rooikrans
  • Rooikrans is a rounded evergreen shrub or small tree.
  • It has straight phyllodes that look like leaves.
  • Rooikrans produces delicate bunches of bright yellow flowers like small pom-poms from late spring to autumn.
  • Clusters of twisted seed pods remain on the plant after releasing the seeds. The black seeds are encircled by a bright red aril that attracts birds.

 

 

 

 

 

 

 

 

Rooikrans (Acacia cyclops): From introduction to invasion:
  • Rooikrans was introduced from Australia to stabilize sand dunes at a time when drift-sands were a big problem in Cape Town, covering roads, buildings and farmland.
  • It produces good firewood and is also used for shade and stock feed (leaves and pods).
  • Rooikrans grows well on poor soils because it has symbiotic Nitrogen fixing bacteria in its roots.
  • It invades fynbos, sand dunes, roadsides and watercourses.
  • It produces huge numbers of seeds, which are spread by birds and can lie dormant in soil for a long time before germinating.
  • Rooikrans is a problem because it threatens biodiversity, increases the severity of fire, and reduces water run-off.

 

 

 

 

 

Rooikrans (Acacia cyclops): Controlling Rooikrans
 
  • You can get rid of Rooikrans by chopping it down. If you cut it close to ground level, it will not re-sprout and you won’t need to paint the stumps with herbicide
  • You can also control Rooikrans using biological control. Two biological control agents exist:
    • A weevil (Melanterius servulus) was first released in South Africa in 1994. It feeds on Rooikrans flowers and the developing seeds. The female weevil lays eggs in the seed pods and the larvae feed on the seeds as they grow. This reduces the number of seeds that are produced.
    • A midge (Dasineura dielsi) forms galls or swellings on the plant. The female midge lays eggs on the flowers. The plant produces galls instead of seed pods and the midge larvae and pupae develop inside the galls. The galls look like withered pods.
  • Although the midge was released after the weevil, it has spread faster and further than the weevil. One reason is that it can have more than one life cycle per year, compared to the weevil that has only one.
  • In South Africa you need special permission to grow Rooikrans. Otherwise you must remove it from your property.

 

 

 

 

 

Rooikrans (Acacia cyclops)
Terrestrial plants:      Aquatic plants Terrestrial animals: Aquatic animals
Kikuyu Grass Water Hyacinth Argentine Ant Largemouth Black Bass
Port Jackson Willow Parrot's Feather European Starling Common Carp
Rooikrans Spanish Reed Feral Cat European Mallard