Water Hyacinth
Eichhornia crassipes
Water Hyacinth
Description
Water hyacinth plants consist of a free-floating rosette of shiny rounded leaves with thick masses of feathery roots which hang in the water. The roots are dark in colour and can reach 2.5 m in length. A single flowering stalk with a cluster of mauve-blue flowers, each with a yellow spot, is produced from the rosette. The stalk grows up to 50 cm above the leaf canopy. Plants produce floating horizontal stems from which new plants arise. Mature mats of this plant are held together by these stems.
Impact
Water hyacinth forms dense mats, completely smothering large waterways and badly affecting water quality. These mats kill off native plants, attract breeding mosquitoes, block dams and irrigation systems, remove oxygen from the water and create a drowning risk for people and animals.
What to do
All sightings must be reported to Biosecurity New Zealand on 0800 80 99 66.
MAF contracts a monitoring and control programme aimed at eliminating water hyacinth from New Zealand.
Useful Links
Eichhornis crassipes (Water hyacinth) Fact Sheet - Florida Exotic Pest Plant Council
http://www.fleppc.org/ID_book/Eichhornia crassipes.pdf 
Please also see the water hyacinth fact sheet 
(210 KB).
Page last updated: 21 August 2009