Status: present in WA
A free-floating plant widespread throughout the tropics, with a dense rosette of overlapping leaves on a very short stem and long feathery roots. Reproduces vegetatively and by seed.
Stems: To 60 centimetres long, linking the rosettes.
Leaves: Pale yellow-green or grey-green, fan shaped, with six or more prominent veins on the under surface, 2.5-15 centimetres long and to eight centimetres wide, densely covered with short white hairs which trap air and give the plant the ability to float.
Flowers: Inconspicuous, surrounded by a small leaf-like bract 7-12 millimetres long and five millimetres wide that encloses the minute male and female flowers.
Fruit: Fleshy, five to eight millimetres diameter.
Seed: Each seed is two millimetres long. Green at first brown when mature, oblong with a thick wrinkled coat, four to 15 seeds per fruit.
Agricultural and economic impact
An environmental water weed, can block irrigation channels.
Declared pest category
The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in Western Australia (WA). Use the external links on this page to reach water lettuce in WAOL.
Requirements for land owners/occupiers and other persons
Requirements for land owners/occupiers and other persons if this pest is found can be sourced through the declared plant requirements link.
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Control methods for this declared plant can be found through the water lettuce control link.