Water Chestnut
Impenetrable mats of water chestnut can cover large expanses of water, altering water quality and clarity, eliminating the growth of native aquatic plants, and making boating, fishing, and swimming hazardous.
Common Name: Water chestnut
Scientific Name: Trapa natans
Native Range: Europe, Asia
Background
Water chestnut is a fast-growing, floating annual that can grow to 16 feet in water depth. It has feathery, submersed leaves and triangular, toothed, floating leaves that are glossy. Floating leaf stalks have visible bulbous bladders and commonly form rosettes. Flowers with four white petals normally bloom in July. The most distinctive trait of this plant is its thorny four-spined nutlets which mature in late summer. Reproduction occurs from these very sharp nutlets and from fragmentation of the rosettes.
Habitat
Water chestnut is found in quiet, high nutrient waters with soft substrate and neutral to alkaline pH.
NYS Distribution Map
NOTE: If you receive a “sign in” message, click cancel to continue. Confirmed observations of Water chestnut submitted to the NYS Invasive Species Database. For more information, visit iMapInvasives
Identification
Water chestnut has large rosettes of glossy, triangular floating leaves that are toothed. It also has feathery, submersed leaves. The floating leaf stalks have visible bulbous bladders and it produces thorny, four-spiked nutlets in late summer.
Impact
Impenetrable mats of water chestnut can cover large expanses of water, altering water quality and clarity, eliminating the growth of native aquatic plants, and making boating, fishing, and swimming hazardous.
Prevention and Control
Small populations can be controlled by hand pulling prior to the release of the nutlets. Large infestations have been controlled in the Northeast by the use of mechanical harvesters or the application of aquatic herbicides.
