Ceratophyllum demersum is an aquatic species, submersed or floating near the surface of the water. It lacks roots and is often found to be unattached to the substrate, though the stem may occasionally be anchored in the substrate by the stem and lower (modified) leaves. Leaves are whorled around the stem at each node and are dichotomously branched once or twice (see leaf photos). The ultimate divisions bear coarse teeth, typical few and far apart, and therefore perhaps appearing as small spines.

Ceratophyllum demersom is extremely common in Wisconsin, usually in calm water and doing best in well-nourished conditions.