Floating water chestnut

Trapa spp.

Schedule 2 Restricted Matter

Biosecurity Queensland must be contacted within 24 hours of sighting, call: 13 25 23.

family

Trapaceae

origin

Exotic

declaration

Category 1 Restricted Matter (Biosecurity Act 2014)

Category 1 Restricted Matter (Biosecurity Act 2014)

Category 1 – must be reported to a Queensland Government inspector within 24 hours

Common names

Water chestnut, Water caltrop.

An annual, floating aquatic plant with the stems (up to 5 m long depending on water depth) rooted in the bottom mud of the water body. The leaves are produced in rosettes and are serrated, waxy and triangular. The white flowers have four petals and are produced in the centre of the floating rosette.The fruit is a hard seed pod containing a single seed; the pod has two or four extremely sharp, barbed spines or "horns"., Floating water chestnut is a prohibited invasive plant under the Biosecurity Act 2014.

Leaf arrangement:Simple
Leaf form:Alternate
White
Green

Impact

Impact

Floating water chestnuts (Trapa spp.) can have extremely detrimental effects on a fresh water environment. Severe infestations can produce up to three successive layers of the plants on the water surface and the subsequent reduction of light to the bottom of the water body will eliminate native plants that normally would be present. Oxygen levels in the water beneath the infestation become lower and eventually lethal to fish and other native organisms. The overall effect is the smothering and destruction of the native aquatic flora and fauna.  The plant does not provide food for bird life which consequently abandon the infestation area., The heavy infestations of Trapa spp. can affect human activities such as fishing, boating or swimming. The plants can clog irrigation facilities. In addition, the extremely sharp seeds are capable of penetrating footwear and causing personal harm. The massed plants can also provide better habitat conditions for mosquito breeding.

Location

Location

Characteristics

Characteristics

Similar Species

Similar Species

Control Methods