Trapa bicornis

Osbeck

Water caltrop, Chinese water chestnut

LythraceaeLeavesSeeds/NutsPotential hazards — see below

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What to Eat

Edible parts: Seeds, Vegetable

The seed is edible when cooked. It has a crunchy texture and a bland flavour. The seed is rich in starch, but contains a harmful principle in its raw state that is destroyed by cooking. Once cooked, the seed can also be dried and ground into a powder.

Known Hazards

Where to Find It

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.

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

Countries: United Arab Emirates, Afghanistan, Armenia, Azerbaijan, Bangladesh, Bahrain, Brunei, Bhutan, China, Georgia, Indonesia, Israel, India, Iraq, Iran, Jordan, Japan, Kyrgyzstan, Cambodia, North Korea, South Korea, Kuwait, Kazakhstan, Laos, Lebanon, Sri Lanka, Myanmar, Mongolia, Maldives, Malaysia, Nepal, Oman, Philippines, Pakistan, Qatar, Saudi Arabia, Singapore, Syria, Thailand, Tajikistan, Timor-Leste, Turkmenistan, Turkey, Taiwan, Uzbekistan, Vietnam, Yemen

How to Identify

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.

How to Grow

An aquatic plant, floating by means of inflated petioles, it succeeds in still or slowly-flowing water requiring a position in full sun and a slightly acidic water with a rich planting medium. Plants require a high summer temperature in order to perform well, they are not frost hardy. Some botanists regard this species as no more than a part of the one highly polymorphic species T. natans. This species was used for food in Neolithic Britain.

Propagation: Harvest seed in late summer and store it overwinter in a jar of water in a cool but frost-free location. The seed loses viability rapidly if allowed to dry out. In spring, sow one seed per pot and submerge under a few centimetres of water.

Medicinal Uses

The flowers are astringent and useful in cases of flux. The fruit is used in the treatment of fever and sunstroke. The plant as a whole has anticancer, antipyretic, and tonic properties.

Other Uses

None known

Wikipedia

Source ↗

A perennial aquatic plant hardy to UK zone 5. Hermaphroditic with both male and female organs. Grows in light sandy, medium loamy, and heavy clay soils with mildly acidic to neutral pH. Requires full sun and can grow submerged in water.

Other Information

It is a commercially cultivated vegetable.

Notes

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

Names & Synonyms

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

Trapa bispinosa Roxburgh

References (24)

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