Water caltrop

Illustration Trapa natans1

Water caltrop 1

Trapa natans0

Trapa natans seeds

Water-caltrops

Leiden University Library - Seikei Zusetsu vol. 28, page 024 - 芰 - Trapa sp, 1804

Water caltrop is a term used to refer to several aquatic plants that produce edible seeds. These plants belong to the family Lythraceae and are commonly found in freshwater environments. The most well-known species include Trapa natans and Trapa bicornis, which are often cultivated for their seeds, also known as water chestnuts.

Description[edit | edit source]

Water caltrops are floating annual aquatic plants with a rosette of leaves that float on the water's surface. The leaves are triangular or diamond-shaped with serrated edges. The plants produce small, white flowers that give way to the distinctive horned seeds. These seeds are typically black and have a hard shell with two or four spines, resembling the shape of a bull's head or a bat.

Habitat[edit | edit source]

Water caltrops thrive in slow-moving or still freshwater bodies such as ponds, lakes, and rivers. They prefer nutrient-rich waters and can often be found in temperate and tropical regions.

Cultivation and Uses[edit | edit source]

The seeds of water caltrops are harvested for their edible kernels, which are consumed in various culinary traditions. They can be eaten raw, boiled, or roasted and are often used in traditional Asian dishes. In addition to their culinary uses, water caltrops have been used in traditional medicine for their purported health benefits.

Ecological Impact[edit | edit source]

While water caltrops are valued for their edible seeds, they can also become invasive in non-native environments. Their dense growth can obstruct waterways, outcompete native vegetation, and disrupt local ecosystems. Management and control measures are often necessary to prevent their spread in affected areas.

Species[edit | edit source]

Trapa natans - Also known as the European water chestnut, this species is native to Europe, Asia, and Africa.
Trapa bicornis - Commonly referred to as the Chinese water chestnut, this species is primarily found in Asia.