What exactly is water cabbage, can you eat it, and what harm does it cause?

Affected by recent continuous rainfall in the upper reaches of the Yangtze River, a large amount of floating debris has appeared on the surface of the river along the Yangtze, stretching on without end and looking like algae from a distance, causing a certain impact on ship navigation and mooring. These floating objects that have “taken over” the river surface are commonly known as water cabbage. What exactly is water cabbage? Can you eat it? What kind of harm does it cause?

Water cabbage: also called water lotus or large-leaf lotus, with the scientific name Pistia stratiotes, it is a perennial floating aquatic herb, monoecious, and reproduces rapidly. It is the number one natural enemy of agricultural environmental protection and has been included in China's list of the 100 most dangerous invasive species. Pistia stratiotes is an exotic species native to Brazil, and is now widely distributed in tropical and subtropical regions. Large-scale occurrences of Pistia stratiotes have also appeared in many inland lakes in South China and East China.

Can water cabbage be eaten

Water cabbage is an annual herbaceous plant. It has a shallow root system, a conical main root, well-developed fibrous roots, strong regenerative ability, and slow growth at the seedling stage. It grows relatively abundantly in the wild in the Pearl River Delta region of China. The rhizome of water cabbage is tender and contains little crude fiber, so it is used as pig feed. But in fact, water cabbage is also a Chinese medicinal herb whose leaves can be used as medicine. Applied externally, it can resolve unnamed swellings and toxicities; boiled in water, it can be used to wash sweat marks, itching caused by blood heat, and to reduce swelling and pain from bruises.

A perennial floating herb, with well-developed feathery roots hanging suspended in the water. The main stem is shortened and the leaves are clustered on it in a rosette shape, with stolons spreading out in all directions from the leaf axils, and new plants emerging from the tips of the stems, with white bundles of fibrous roots. Leaves are clustered, with obovate-cuneate blades, 2-8 cm long, with blunt rounded tips that are slightly wavy, and white fine hairs on both sides. The inflorescence grows in the leaf axils, with a short peduncle, and a spathe about 1.2 cm long, white, with hairs on the back. The fruit is a berry, containing 10––15 seeds, elliptical, yellowish-brown. The flowering period is June to July.

Efficacy and effects of water cabbage

The whole plant is used as pig feed. Used as medicine externally for unnamed swellings and toxicities; boiled in water it can be used to wash sweat marks, itching caused by blood heat, and to reduce swelling and pain from bruises; decocted in water and taken internally it can promote menstruation, and treat edema, difficult urination, sweat rash, ecthyma, and water gu (Jingzhou). The leaves are used as medicine. Harvested in summer and autumn, dried in the sun.

[Nature, flavor, and meridian entry]Pungent, cool.

[Functions and indications]Dispels wind and induces sweating, promotes urination and detoxifies. Used for colds, edema, difficult urination, rheumatic pain, skin itching, urticaria, and incomplete eruption of measles; external use treats sweat spots and eczema.

[Usage and dosage]3-5 qian; appropriate amount for external use, apply the juice of fresh material or decoct in water to wash the affected area.

Ornamental application

In garden waterscapes, it is often used to accent the water surface. In a small courtyard pond, planting a few clusters of Pistia stratiotes and raising several carp makes the environment elegant and natural, with a distinctive charm. It has well-developed roots that directly absorb harmful substances and excess nutrients from sewage, and can purify water bodies.

Is water cabbage toxic

Non-toxic.

Although water cabbage is very effective at dispelling wind and inducing sweating, promoting urination and detoxifying, it is not suitable for everyone. Experts say that pregnant women with special constitutions need to avoid taking it, otherwise it will have adverse effects on the body. Therefore, everyone is advised to be cautious and pay attention in daily life, especially to the dosage. If you are unclear about the medicinal properties and pharmacology, it is best to consult a professional doctor before use, which is the safe and reliable approach.

The harm of water cabbage

Water cabbage itself has very high nutritional value, but the growth capacity of this plant does indeed exceed the carrying capacity of the environment. This is true of everything, and there needs to be a limit. If water cabbage grows unchecked, then it will cause these harms:

A large amount of water cabbage floating on the river surface endangers navigation safety. During the day, when some large ships are sailing, it can be seen clearly. But when sailing at night, if you see such a large mass drifting on the river surface, you may worry about a collision and need to slow down or stop the ship.

Ecological harm:

(1) Water cabbage has well-developed roots and needs to consume oxygen in the water body during its growth process, causing oxygen concentration to become too low and leading to large-scale suffocation and death of fish.

(2) Large-scale reproduction of water cabbage will cover the entire water surface, causing underwater plants to die and rot because they cannot carry out photosynthesis, and it will also cause fatal harm to aquatic animals. In addition, the death, deterioration, and rotting of water cabbage itself further intensifies the death of animals.