Water Chestnut
Trapa natans
Family: Trapaceae
What it is like
Trapa natans is a PERENNIAL. See above for USDA hardiness. It is hardy to UK zone 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: mildly acid and neutral soils. It cannot grow in the shade. It can grow in water.
Height (m): 0
Where it is found
Water up to 60cm deep.
Europe to E. Asia, Indo-China and N. Africa.
Conservation Status: Status: Least Concern
Countries/locations it is found in
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,
How it is used
Food
Rating: 4
Seed - raw, cooked or dried and ground into a powder. A sweet floury and agreeable flavour, similar to sweet chestnuts (Castanea spp). The seed contains up to 50% starch according to one report, 16% starch, 3% protein in another report and 15% protein, 7.5% fat in a third. (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.
Seed: includes nuts, cereals, peas and beans.
Medicine
Rating: 2
The fruits are used in the preparation of liniments to treat elephantiasis, pestilent fevers, rheumatism, sores, sunburn and skin complaints.
Antirheumatic: Treats rheumatism.
Febrifuge: Reduces fevers.
Skin: Plants used in miscellaneous treatments for the skin.
Other
Rating: 2
The seeds are sometimes used as beads in necklaces and rosaries. The plant can be free-floating in the water, or rooting in the mud in shallow water. It is also able to grow out of water in very wet, muddy soils. The plant is also grown as an ornamental in aquaria and outdoor ponds.
Beads: Used as necklaces etc.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
How it is grown
A water plant, growing in water up to 60cm deep. Requires a sunny position in slightly acidic water. Dislikes calcium rich water. Prefers a rich soil. Plants are hardy in all but the coldest parts of Britain. A perennial, but it is best grown as an annual in Britain. 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. Occasionally cultivated for its edible seed, there is at least one named variety. 'Su Zhou' is a form with red-coloured fruit.
Propagating it: 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.
Best place to grow: Pond;
Habit: Perennial
Hardiness: 6-12
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Water
Things to keep in mind
The raw seed contains toxins but that these are destroyed in the cooking process.
Its other names
Local names
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).