Abstract Potamogeton natans L. is a widespread floating-life macrophyte of high ecological relevance in freshwater ecosystems. By contributing to oxygenation, habitat structure, water clarity and nutrient cycling, it plays a key role in ecosystem functioning, although under favourable conditions it can form dense stands that impair water flow, irrigation and navigation. This review integrates current knowledge of the species’ taxonomy, morphology, distribution and ecological impacts, with a part