What is the term for aquatic plants that grow completely underwater?

The term for aquatic plants that grow completely underwater is "submersed." These plants live entirely beneath the water's surface, and they have adapted to thrive in aquatic environments where they can photosynthesize while submerged. This adaptation allows them to take up nutrients and oxygen directly from the water.

In contrast, emersed plants are those that grow partially above the water, often having their roots anchored in the substrate while their stems or leaves extend into the air. Free-floating plants float on the water's surface, not anchoring themselves to the substrate, and they generally rely on water for support. Rooted-floating plants are a type that has roots submerged in the water but leaves that float on the surface, thus not fully underwater. Understanding these distinctions is crucial for effective aquatic pest management, as the different growth forms of aquatic plants can influence their role in an ecosystem and the strategies needed to manage them effectively.