Water chestnuts are a problem every year for the fishermen of the Danube Delta, but the elders of the villages isolated by waters know that they can eat the fruits of this plant just as people eat popcorn in cinemas, in big cities and that its abundance indicates the level of clogging of the lakes and canals in the Reserve, according to Agerpres.
The water chestnut, also known as water nut, horned water chestnut, water caltrop, bull nut, bat nut, devil pod, has the scientific name Trapa natans and is an annual aquatic species, with roots that develop in the fresh mud of lakes or canal edges. The plant stretches its stems to the surface of the water, where they support a rosette of about 30 floating diamond-shaped leaves.
The petiole of the leaves has a bulge in the middle, an air chamber, which in section looks like a sponge full of air. This natural raft not only maintains the buoyancy of the rosette of leaves, but is sufficient to support a nest of marsh terns – the Black Tern (Chlidonias nigra L.) and the Whiskered Tern (Chlidonias hybrida Pall.), species of colonial water birds, which use, among others, these plants as a support.
Thriving in areas with freshly deposited mud, this species is an indicator of clogging of lakes and canals in the Delta.
„The plant is protected by the Bern Convention, but in the Danube Delta it is very widespread, and sometimes due to its abundance it prevents the movement of boats and barges,” reads a material provided by the Danube Delta National Research-Development Institute (INCDDD) .
The flowers of the plant are bisexual, small, white, and the fruit is hard, fleshy, 2-4 centimeters long, with two or four thick, rigid horns. The name Trapa is derived from the Latin term calcitrapa, a weapon used against cavalry attacks, which had four points, horns, like the hornbeam fruit. When it is ripe, the fruit detaches from the stalk and falls like an anchor to the bottom of the water, in order to generate a new plant in the next growing season.
Some Delta fishermen recognize the species by the leaves and remove the plants from the water and let them dry. After a few days, they break the horns of the fruit with a knife, remove their almost woody skin and eat the crunchy core with a slightly sweet taste.
„The plant is frequently found in stagnant or slow-flowing waters, and if it was initially widespread in the Eurasian area and North Africa, it has recently reached other continents. In some states, it is cultivated as a food plant, given that the seeds contain about 52% starch and 15% protein,” mention the INCDDD representatives.
Some old fishermen remember that, when they were children, water chestnuts were prepared by their parents in large cauldrons and were eaten in winter evenings in front of the televisions, just as popcorn is eaten in cinemas in big cities these days. It was used as a food resource by the inhabitants of the Delta during the famine after the Second World War.
In folk medicine, the fruits of water chestnuts are used as a medicine against rabies and the bites of some poisonous animals.
The leaves of the plant have fodder value for pigs and horses. Wild boars are also looking for the fruits of the water-caltrops before the cold season.
In China, water chestnuts are grown in fields flooded with rice, and harvesting is difficult, which is why the price is very high.
The skin of the water chestnut fruits is dark brown in color, and the white core has a rounded shape like a heart, crunchy, with a very pleasant texture. They can be eaten boiled, roasted, pickled or preserved.
Water chestnuts are rich in anti-oxidants and anti-inflammatory compounds. These compounds are said to help correct digestive problems, anemia and fatigue. They can also reduce fever, pain and inflammation, support diabetes management, have anti-oxidant and anti-cancer effects, lower blood pressure and have anti-microbial activity.