Gemeiner Wasserhahnenfuss

<em>Ranunculus aquatilis</em>, commonly known as the common water crowfoot or white water buttercup, is an aquatic flowering plant in the family Ranunculaceae. It is classified as Least Concern by the IUCN and enjoys a nearly cosmopolitan distribution, occurring in freshwater habitats across Europe, Asia, North America, and parts of Africa and South America. The species typically inhabits ponds, ditches, slow rivers, and streams, where it roots in sediment and produces both submerged finely divided leaves and floating rounded leaves. The white five-petaled flowers emerge above the water surface from spring through early summer, providing important nectar resources for pollinators. <em>Ranunculus aquatilis</em> is highly adaptable, with leaf morphology shifting according to water depth and flow velocity. Submerged leaves are thread-like and flexible, reducing drag in flowing water, while floating leaves are broad and rounded to maximize light capture. The plant typically reproduces both sexually through seed production and vegetatively through fragmentation of stems and rhizomes. Biological traits including average lifespan, height, and mass remain poorly documented in standardized databases. Ecologically, common water crowfoot is a foundational species in many freshwater plant communities, providing structural habitat for invertebrates and small fish, contributing to oxygenation, and serving as a food source for waterfowl and aquatic herbivores across its wide global range.