American rat's tail grass

Native to Mexico, Central America, the Caribbean and South America, American rat's tail grass is a clumping grass that invades pasture and replaces more productive grasses.

American rat's tail grass looks very similar to giant rat's tail grass and even experts have difficulty differentiating the two.

You must manage the impacts of American rat's tail grass on your land.

You must not give away, sell or release American rat's tail grass into the environment.

Scientific name

Sporobolus jacquemontii


  • Upright, densely tufted perennial grass up to about 1m tall.
  • Leaf blades up to 40cm long, 2.5–33mm wide.
  • Seed head is 8–25cm long, spikelets 1.5–2mm long.
  • Looks very similar to giant rat's tail grass but is shorter.


  • Can adapt to a wide range of soils and conditions.


  • Found in coastal regions of northern and Central Queensland.
  • Scattered in South East Queensland.
  • Visit Weeds Australia and click on the distribution tab to access the distribution map.

Life cycle

  • Flowers throughout the year.



  • Invades pastures.
  • Replaces more productive grasses.

How it is spread

  • Seed spread by water, wind and machinery.


  • Control strategies for American rat's tail grass are similar to control strategies for giant rat's tail grass.

Biological control

  • No known biological control agents.

Legal requirements

  • American rat's tail grass is a category 3 restricted invasive plant under the Biosecurity Act 2014.
  • It must not be given away, sold, or released into the environment. Penalties may apply.
  • You must take all reasonable and practical measures to minimise the biosecurity risks associated with dealing with American rat's tail grass under your control. This is called a general biosecurity obligation (GBO).
  • At a local level, each local government agency must have a biosecurity plan that covers invasive plants in its area. This plan may include actions to be taken on American rat's tail grass. Some of these actions may be required under local laws. Contact your local council for more information.

Further information