Callitriche stagnalis aka Starwort

Callitriche stagnalis, also known as pond water-starwort, is a perennial aquatic vascular plant species. It can be found in a variety of aquatic and subaquatic habitats, particularly in areas with slow to non-moving water. This plant has spoon-shaped, bright green submerged leaves that can grow up to 2cm long, as well as rosettes of broader floating leaves. The stems of C. stagnalis often root into wet mud, forming a dense mat. While it does not pose a threat to humans, its rapid reproduction can be a concern for native vegetation in areas where it has been introduced, as the dense vegetative mats tend to out-compete native species.