Caltrop is a summer growing weed that is often confused with another weed species, the three corner jack. Caltrop is an extremely efficient plant that can flower and set seed within 2-3 weeks of germinating and the burrs are easily transported by people on the bottom of shoes or car tyres and can also cause injury to people or animals. This plant can be difficult to remove completely due to the longevity of the seed in the soil and the plants ability to set seed quickly. Caltrop is declared under the Natural Resources Management Act 2004.