Water caltrop, Chinese water chestnut
Trapa bicornis

Family: Lythraceae

What it is like

A herb which grows in water. It keeps growing from year to year. It has 2 kinds of leaves. The leaves under the water are long and like threads. The floating leaves form rings. They are broad and angular. The leaf stalk to them is swollen in the middle. The fruit are shiny, black nuts which have 2 horns. They are about 6 cm wide. These develop under the leaves near the centre of the plant.

There are 8-15 (30) Trapa species. Also as Trapaceae.

Where it is found

A tropical plant. It grows in still water in warm places. It is cultivated in ponds and canals in rice areas in southern China. It grows in wetlands.

Countries/locations it is found in

Asia, Bangladesh, China, Cambodia, India, Indochina, Japan, Laos, SE Asia, Vietnam

How it is used for food

The nuts need to be boiled for considerable time to remove poison and are then eaten.

It is a commercially cultivated vegetable.

Edible parts

Seeds, vegetable

How it is grown

Its other names

Local names

Black Ling, Horn-nut, Ling kio, Ling nut, Singhara nut, Wu Ling

Synonyms

Trapa bispinosa Roxburgh;