What is the name of the aquatic plant type that is not attached to sediment and floats on or just below the water surface?

Free-floating aquatic plants are those that are not anchored to the sediment at the bottom of a waterbody and float freely on or just beneath the surface of the water. These plants, such as duckweed or water lettuce, can move with the currents and are often found in ponds, lakes, and slow-moving rivers where they can thrive in illuminated areas.

In contrast, submersed plants grow entirely underwater and are anchored to the substrate, while rooted-floating plants have roots that hold them in place but allow their leaves and stems to float on the surface. Emergent plants, on the other hand, are anchored in the sediment but extend above the surface of the water. The distinguishing characteristic of free-floating plants is their ability to float unhindered by anchoring to the bottom, allowing them to occupy unique ecological niches and play specific roles in aquatic ecosystems.