Emersed and submerged aquatic plants
Aquarium plants can be either emersed (above water) or submerged (under water), depending on their natural habitat.
Emersed: These plants grow above the surface of the water. They can be found, for example, in wetlands or on the banks of natural bodies of water. Emersed plants often have different leaf shapes and structures compared to their submerged forms. Before they are used in an aquarium, they must be adapted to life underwater.
Submerged: These plants grow completely underwater. They are the ones that are typically used in aquariums. Submerged plants have special adaptations to live underwater, such as finer leaves that facilitate gas exchange and roots that adapt to nutrient uptake in the water.
Most plants used in aquariums are submerged and have been specifically bred to live underwater. However, there are also some plant species that originally grow emersed but can be successfully grown submersed in aquariums after being adapted to underwater conditions.