Freshwater plants

Freshwater plants (often referred to as aquatic macrophytes) occupy the interface between land and freshwater. They extend along a cline of increasing water depth, from terrestrial and riparian vegetation, followed by emergent freshwater plants with leaves in the air and roots in flooded soil, and then plants with leaves at the water surface or completely submerged. Although impossible to define precisely, there are around 5000 species globally. Here, we describe the adaptations of these plants to their environment and how they responded to recent anthropogenic changes. Because they contribute resources to the food web and interact strongly with other biotic components, they act as important ecological engineers altering their environment. These characteristics have enabled freshwater plants to occupy a broad distributional range, be among the world’s most productive plant communities, and provide staple food for more than half of the human population, but also become some of the world’s most invasive pests.