[4] An aquatic plant, Ceratophyllum demersum has stems that reach lengths of 1–3 m (3–10 ft), with numerous side shoots making a single specimen appear as a large, bushy mass.

The leaves are produced in whorls of six to twelve, each leaf 8–40 mm long, simple, or forked into two to eight thread-like segments edged with spiny teeth; they are stiff and brittle.

[10] Ceratophyllum demersum grows in lakes, ponds, and quiet streams with summer water temperatures of 15–30 °C[citation needed] and a rich nutrient status.

[12] Other reported occurrences include China, Siberia (at 66 degrees North), Burkina Faso and in the Volta River in Ghana (Africa), Vietnam, and New Zealand (introduced).

[15] C. demersum has allelopathic qualities as it excretes substances that inhibit the growth of phytoplankton and cyanobacteria (blue-green algae).

[18] One of the reasons for this is that it allows studies on shoot effects without influence of a root, which often makes interpretation of nutrition and toxicity experiments difficult in terrestrial plants.

As it is free floating and therefore does not require a solid substrate, it has been used successfully in the biological life support systems "Aquarack/CEBAS" and "Omegahab" on space flights.