Species sheet · The Edible River
Water caltrop
The horned nut that floats on ponds.
- Boiled then shelled, eaten warm
- As singhara flour for the flatbreads and halwa of Indian fasting days
- Stir-fried with vegetables, Chinese style (ling jiao)
- In French
- Mâcre
- Scientific name
- Trapa natans
- In the water
- A floating plant of calm ponds and lakes in Europe and Asia. Its rosettes of toothed leaves cover the surface, and its fruits ripen underwater.
- Season & buying
- Fruits harvested from September to November; in India, fresh singhara is sold by the roadside in autumn. Protected in the wild in Europe (Bern Convention): buy it farmed, as singhara or ling jiao, from Indian and Chinese grocers.
- Common length
- ~40 cm
- How to identify it
- Rosette of diamond-shaped toothed leaves on swollen stalks
Hard black fruit armed with two to four sharp horns
White, starchy kernel inside the shell
On the plate
White kernel, crunchy raw, starchy and sweet once cooked, somewhere between chestnut and potato.
Avoid: Biting it raw straight from the pond: fruits from stagnant water can carry intestinal flukes; always cook it, and mind the horns, which pierce skin.
Remains turn up in the Neolithic lake villages of the Alps: water caltrop already fed the people of the houses on stilts.
In Umay recipes
2 Umay recipes call for it.
