Callitriche cophocarpa, commonly known as Water Starwort, is a perennial herb that is semi-evergreen and native to a variety of aquatic environments across Europe, Russia, and Northern Africa, including slow-moving streams, ponds, and shallow lakes. This plant typically forms dense mats on the water’s surface or partially submerged. Water Starwort has a modest growth rate and can spread to cover significant areas in suitable conditions. It generally reaches up to 6 inches (15 cm) in height and can spread widely across the water surface.

Water Starwort is valued for its ability to oxygenate water and provide habitat for aquatic wildlife. It has small, inconspicuous green flowers that appear from late spring to early autumn, which are not particularly showy but are interesting upon close inspection. In cultivation, it is used primarily in water gardens, ponds, and aquariums. It prefers full sun to part shade and requires standing or slow-moving water to thrive. While it is not demanding in terms of soil nutrients, it does best in neutral to slightly alkaline pH conditions. Water Starwort can be a useful plant for natural filtration in water features. However, it can become invasive in some regions outside its native range, so care should be taken to control its spread to prevent it from outcompeting native aquatic plants.CC BY-SA 4.0