Water caltrop

Trapa natans
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See it - Report it

Early detection is vital to stop Water caltrop becoming established in South Australia.
If you see this weed, please report it to the National Pest Alert Hotline (Freecall) 1800 084 881.

Freecall 1800 084 881

Weed profile

  • Annual
  • Reportable
  • Habitat: gardens, waterways

Impact

Forms dense mats over water. Spiny fruits. Not present in Australia.

Description

  • Annual aquatic herb, may be free-floating or anchored to mud.
  • Rosette of fan-shaped leaves with toothed edges.
  • Flowers white with 4 petals.
  • Fruits hard nuts with four sharp spines.

Control options

  • physical control

    Manual removal

    When: When found.

    Where: Aquatic habitats.

Manual removal

Situation: Aquatic habitats.

Timing: When found.

Comments: Skim plants off the water and dispose by drying or composting. Seek advice from your regional landscape board first. Monitor site until eradication has been achieved.

Legal requirements in each region

To find out which landscape region you're in visit the NatureMaps website.
Alinytjara Wiluṟara
Eyre Peninsula
Green Adelaide
Hills and Fleurieu
Kangaroo Island
Limestone Coast
Murraylands and Riverland
Northern and Yorke
South Australian Arid Lands