A Complete Guide to the Characteristics and Cultivation Uses of Hornwort

Hornwort (Ceratophyllum demersum) is a perennial submerged herbaceous plant in the genus Ceratophyllum, family Ceratophyllaceae, commonly found in still or slow-flowing water bodies such as ponds, lakes and ditches. Its stems are slender and soft, and its leaves are whorled and divided into thread-like segments, with the whole plant submerged in water. Although its name contains the word "fish", it is in fact not related to goldfish at all; it simply got its name because it is often kept in fish tanks.

Hornwort has no true roots; it mainly anchors itself by having its stems inserted into the bottom sediment, and it can also grow floating free of the substrate. It likes light, and grows vigorously when light is sufficient; during the day it can release oxygen into the water, which is very helpful for improving the aquatic environment. Other common species in the same genus include Ceratophyllum manschuricum, Ceratophyllum demersum var. quadrispinum and Ceratophyllum submersum, which are similar in appearance and mostly differ in the way the leaves are divided and the shape of the fruit spines.

In terms of uses, hornwort is often used as an ornamental aquatic plant, and it is also a good place for fish and shrimp to perch, hide and spawn; it can additionally serve as green fodder for herbivorous fish. Planted in appropriate amounts in ponds or rice fields, it can absorb excess nutrients from the water and inhibit the excessive reproduction of other algae, thus playing a certain water-purifying role. In addition, after being harvested it can be composted for use as green manure.

When caring for hornwort, pay attention to light and water temperature; long-term insufficient light tends to cause the leaves to turn yellow and drop off. When the plants grow too densely, they should be harvested and thinned out in good time to avoid covering the water surface and affecting light penetration and dissolved oxygen. Overall, hornwort is highly adaptable and reproduces quickly, making it a very common and practical aquatic plant in water landscaping and aquaculture.