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Trapa natans - L.

Common Name Water Chestnut
Family Trapaceae
USDA hardiness 6-12
Known Hazards The raw seed contains toxins but that these are destroyed in the cooking process[200, 206].
Habitats Water up to 60cm deep.
Range Europe to E. Asia, Indo-China and N. Africa.
Edibility Rating    (4 of 5)
Other Uses    (2 of 5)
Weed Potential Yes
Medicinal Rating    (0 of 5)
Care (info)
Fully Hardy Water Plants Full sun
Trapa natans Water Chestnut
Trapa natans Water Chestnut


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Physical Characteristics

Trapa natans is a PERENNIAL.
It is hardy to zone (UK) 5. It is in flower from June to July. The species is hermaphrodite (has both male and female organs).
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: acid and neutral soils. It cannot grow in the shade. It can grow in water.

UK Hardiness Map US Hardiness Map




Edible Uses

Edible Parts: Seed
Edible Uses:

Seed - raw, cooked or dried and ground into a powder[2, 3, 13, 34, 56, 63, 74, 100]. A sweet floury and agreeable flavour[27], similar to sweet chestnuts (Castanea spp)[183]. The seed contains up to 50% starch according to one report[46], 16% starch, 3% protein in another report[117] and 15% protein, 7.5% fat in a third[74]. (Are all these reports talking about the same thing?). One report says that the raw nut contains toxins that are destroyed by cooking the seed[200].


Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.

None known


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Other Uses

None known

Special Uses


Cultivation details

A water plant, growing in water up to 60cm deep. Requires a sunny position in slightly acidic water[200]. Dislikes calcium rich water[50]. Prefers a rich soil[50, 56, 200]. Plants are hardy in all but the coldest parts of Britain[1]. A perennial, but it is best grown as an annual in Britain[3]. Some botanists regard this species as the only genuine member of the genus, all other species considered to be no more than a part of this one highly polymorphic species[200]. Occasionally cultivated for its edible seed, there is at least one named variety[1, 3, 13]. 'Su Zhou' is a form with red-coloured fruit[183].


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Seed - harvest in late summer and store overwinter in a jar of water in a cold but frost-free place. The seed quickly loses its vitality if it is allowed to become dry. Sow in spring, placing one seed in each pot and submerging them under a few centimetres of water.

Other Names

If available other names are mentioned here

Dyavolski oreh, European water chestnut, Heikak, Horn nut, Ling-chio, Rasac, Saligot, Shinghada, bat nut, buffalo nut, charcoal tree|diya ikili / ikiliya, devil pod, gara, gaunaree, horn nut, jalaphala, jalaphalam, jalfal, karimpola, karimpolam, kubyakam, paniphal, paniphala, shingoda, simgara, simgoda, singada, singade, singhada, singhade, singhara, singoda, srngataka, triko?aphala, vankotta, water caltrop, water chestnut, sr?gata, s??ga?aka (dried seed).

Found In

Countries where the plant has been found are listed here if the information is available

Africa, Albania, Algeria, Asia, Australia, Austria, Balkans, Belarus, Bosnia, Bulgaria, Burma, China, Czech, East Africa, Europe, France, Germany, Greece, Hungary, India, Italy, Japan, Mozambique, Myanmar, Nigeria, North Africa, North America, Pakistan, Poland, Romania, SE Asia, Slovakia, Spain, Switzerland, Tunisia, Turkey, Ukraine, USA, West Africa, Yugoslavia,

Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Conservation Status

IUCN Red List of Threatened Plants Status : Status: Least Concern

Related Plants
Latin NameCommon NameHabitHeightHardinessGrowthSoilShadeMoistureEdibleMedicinalOther
Centaurea calcitrapaCommon Star Thistle, Red star-thistleBiennial0.6 0-0  LMHNDM11 
Tetrapanax papyriferRice Paper Plant, Chinese Rice Paper PlantShrub5.0 8-11 FLMHSNM11 
Trapa bicornisLing, Horn nutPerennial0.0 4-8  LMHNWa41 
Trapa incisa Annual0.0 -  LMHNWa10 
Trapa japonica Annual0.0 -  LMHNWa10 

Growth: S = slow M = medium F = fast. Soil: L = light (sandy) M = medium H = heavy (clay). pH: A = acid N = neutral B = basic (alkaline). Shade: F = full shade S = semi-shade N = no shade. Moisture: D = dry M = Moist We = wet Wa = water.


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Botanical References


Links / References

For a list of references used on this page please go here
A special thanks to Ken Fern for some of the information used on this page.

Readers comment

michele   Sun Mar 4 2007

i would like to have the seeds of tis plant. how is it possible? thnaks michele

Ken Fern, Plants for a Future.   Mon Mar 5 2007

Unfortunately, the seeds of this plant need to be kept moist otherwise they quickly lose their viability. For this reason, there are no seed suppliers that I am aware of. There are a few nurseries that supply the plant - the only one I know of is in Britain, though it does mail order to all countries in the European Union. For details of this nursery visit the Plant Finder at

HK   Tue Jan 29 2008

I am not sure about the criteria, but I really think you guys need somebody who is familiar with TCM, Kampo or whatever. Just because you guys don't know does not mean that a given species does not have any notable medicinal property or importance in indigenous medicine. I just keep encountering this over and over here.

Keith   Mon Aug 11 2008

Also can be highly opportunistic (ie. 'invasive')-

Burlington Free Press Article Article about efforts 'combating' water chestnut

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