Water chestnut - Trapa natans


The water chestnut is a perennial aquatic plant native to most of Asia, long introduced in Europe and North America. It consists of a dense rosette of floating leaves, toothed, fan-shaped, bright green on the upper side, with thin hair on the lower page. The leaves are attached by means of a long spongy stem. The plant produces real patches of leaves that float on water in areas where the current is less intense and strong. Lakes and ponds are typical areas where this plant grows in abundance.
In spring it produces solitary flowers of various colors ranging from white to deep pink, floating above the leaves. Below the rosette grow the roots that sink into the ground. In summer, each flower becomes a woody fruit, which contains a single fleshy seed.
This plant loves sunny exposure but grows very well even in other conditions. The Trapa natans suffer very cold winters and where temperatures are very cold it is generally cultivated as an annual.
The water chestnut has an edible tuber that is used in many areas as a food. In Italy the Trapa natans tuber can be used as an ingredient in risottos and other dishes but can also be used raw, fried or reduced to flour.


As mentioned in the previous paragraph, this plant prefers positions in full sun, even if it develops without problems in any condition. In places with very cold winters the plant is cultivated as an annual, the plants die completely with the arrival of winter, but every spring from the seeds develops a new rosette of leaves.


The roots of trapa natans essentially have the function of anchoring the plant to the ground, and they do it in any soil; however, the plant does not like limestone-rich waters, preferring slightly acidic ph water. The roots can reach even great depths in the water, reaching up to 5 meters in height.


It happens by seed; the ripe seeds should be stored throughout the winter in a container filled with water, in a cool place away from frost. In spring the seeds are planted in a soil made up of peat and sand in equal parts, in containers that must be kept underwater until the seedlings appear, which are to be planted in autumn or in the spring of the following year. Being a plant that expands rapidly and constantly, the water chestnut can also be multiplied by division, separating a portion of the plant from the mother plant to obtain a new one.

Pests and diseases

As for the pests and diseases of this plant, the Trapa natans is hardly attacked and no particular infestations are reported for this species.

Water chestnut - Trapa natans: Uses in herbal medicine

One of the uses that is made of this plant is the herbal one. The water chestnut can in fact be used by those who love natural cures and phytotherapy for various purposes. For example, with its leaves and fruits it is possible to obtain different preparations. The leaves have soothing and refreshing properties and allow the skin to relax after sunburn and redness.
The seeds are instead used for disorders of the digestive system, such as diarrhea, against which they seem to have a great effect.