Invasive Species (Aquatic) -


Water chestnut / European water chestnut
(Trapa natans L.)


Photos & Description courtesy of IPANE

Where it's from



What Water chestnut / European water chestnut does to the habitat

The water chestnut creates mats at the surface of the water that blocks out all light for native species. It out competes native plants for space and nutrients.


Water chestnut adds little nutritional value for wildlife and yet cause havoc with commercial navigation, fishing, boating and swimming. Its decomposition contributes to lower levels of oxygen dissolved in the water, harming fish and aquatic life.



Pond rakes and pulling by hand are effective, but be sure to bag all plant parts.


If you choose an herbicide use 2,4-D that is licensed for application to water chestnuts.


Common Name

Full Scientific Name

Water chestnut
European water chestnut

Trapa natans L.

Family Name Common

Family Scientific Name

Water-nut family Trapa natans


Botanical Glossary

Lythrum salicaria is an herbaceous wetland perennial that can grow 0.5-1.5 m (1.5-5 ft.) tall. The leaves are either opposite or in whorls of three. The can be pubescent or glabrous. They are lanceolate to linear in shape and 3-10 cm (1-4 in.) long. The larger leaves can be cordate or clasping at their bases. The flowers are purple, magenta or pink. They are numerous and borne on spikes that are between 10 and 40 cm (4-16 in.) long. The hypanthium is linear and twice as long as the sepals. Each flower has 5-7 petals, and the open flowers measure 7-12 mm (0.3-0.5 in.) in diameter. The relative lengths of styles and stamen in these flowers can vary in three different ways. The flowers are in bloom from July to September. The fruits are capsules, each containing numerous reddish-brown seeds. Page References Bailey 719, Crow & Hellquist 203, Fernald 1048, Gleason & Cronquist 311, Holmgren 292, Magee & Ahles 758, Newcomb 351, Peterson & McKenny 224,288.

Previous Image | Back to Gallery | Next Image