The characteristic feature of submersed plants is that they:

Submersed plants are specifically adapted to grow entirely underwater, which allows them to thrive in aquatic environments without exposure to the air. The characteristic of growing completely below the water distinguishes them from other types of aquatic plants, such as floating plants that rest on the surface or emergent plants that grow partially above the water. This adaptation is crucial for submersed plants as they rely on the water column for buoyancy and support, and they often have specialized structures that enable them to absorb nutrients directly from the water. By growing fully submerged, these plants play vital roles in aquatic ecosystems, providing habitat for various organisms and contributing to oxygen production through photosynthesis.