Aquatic plants and where to find them: terms, concepts, and classifications of plants adapted to aquatic environments and their margins

Understanding and conserving wetland vegetation requires a unified framework for classifying plants adapted to aquatic environments. Numerous taxonomic, limnological, and ecological studies have endeavored to establish such a framework. From Eugenius Warming's pioneering work to the latest classifications, this paper provides a historical overview of the various terms, concepts, and criteria used to categorize these plants, considering environmental factors, evolutionary relationships, and functional traits. The biological forms associated with adaptations to flooding, including floating and submerged species, offer valuable insights into the diverse life strategies of aquatic plants within the land-water continuum. This review thoroughly examines the definition of amphibious plants, a complex group that reflects the diversity of landscapes in which they occur, often resulting in sampling biases over time. These plants, reliant on water to complete their life cycle, are adapted to fluctuating water levels typical of waterway margins and exhibit phenotypic plasticity in response to varying degrees of soil water saturation. Finally, we discuss key considerations for sampling techniques to better investigate amphibious plants, such as sampling in different seasons and analyzing hydrological fluctuations in the studied region.

Keywords:
amphibious plants; aquatic macrophytes; classification criteria; hydrophytes; life forms