Water Hyacinth

Eichhornia crassipes

Water Hyacinth

Family: Pontederiaceae

Other Scientific Names:

Eichhornia crassipes

Other Common Names: common water hyacinth
Weed class: monitor list
Year Listed: 1995
Native to: Parts of South America
Is this Weed Toxic?:

not known to be

Why Is It a Noxious Weed?

This plant is on the monitor list - it is not a listed noxious weed in Washington. Please contact its sponsor Wesley Glisson to report locations or for more information.

How would I identify it?

General Description

This floating aquatic plant can grow up to 3 feet above the water surface. Its population can double in size every week. 

Flower Description

Spikes of many 6-petalled lavender to light pink-purple

Leaf description

Spoon shaped, with the side attached to the plant being bulbous with air

Stem description

The only stem this plant grows is the stalk leading to the flowers, which is round, green, and fleshy

Fruit Seed Description

Small, rounded sunflower seed shaped, with light ridges running lenghtwise

Where does it grow?

Escapes from aquariums and ponds, into natural watercourses

How Does it Reproduce?

One of the fastest growing plants, it spreads vegetatively with stolons and rhizomes, as well as by seeds that can stay viable for almost 30 years

How Do I Control It?

Please refer to the PNW Weed Management Handbook, or contact your county noxious weed coordinator.

For More Information

Whatcom County NWCB Fact Sheet on water hyacinth

Additional Photos