Water Chestnut

Trapa natans

Common Name: Water chestnut
Scientific Name: Trapa natans
Family: Trapaceae
Growth Form: Aquatic plant
Native Range: Europe and Asia
Invasive Range: Northeastern United States
Introduction: This plant was introduced to North America in 1874 and was cultivated in the Harvard Botanical Garden, from which it was able to escape into nearby ponds and lakes.
Description: ·Leaves: Two types: below surface of water, leaves alternate and simple. Above water leaves toothed and triangular shaped; form rosettes resting on inflated petioles.

·Stem: Can grow up to 5 m long; submerged.

·Root: Two types of root: lower roots threadlike; upper roots rough and fibrous with few branches. 

·Flowers: Form above surface of water.  Single flower, 4 white petals. About 8 mm (.4 in.) long.

·Fruit: Hard nut with a diameter of about 3 cm (1.5 in.) and 4 sharp protruding spines.
Threats: Water chestnuts grow densely, impacting fisheries and impeding navigation in bodies of water.  They produce sharp seedpods that are painful when stepped on. This makes the water chestnut a particularly unpleasant addition to swimming beaches, where the seedpods can wash ashore and make the beach unusable.
Fun Facts: There are two types of Water Chestnut.  The other kind, a sedge, is a common component of Chinese cuisine.
Plant at water's surface