Sparganium natans, commonly known as least bur-reed, is a perennial herb that thrives in the shallow, calm waters of marshes, ponds, and slow-moving streams. It is native to a wide range of regions including North America, Europe, West Asia, and Japan. This aquatic plant typically has a height of 10-30 cm and features thin, grass-like leaves that can either float on the water’s surface or stand erect when exposed. The least bur-reed is notable for its unique inflorescences, which consist of separate rounded white staminate (male) and green pistillate (female) flower spheres, blooming from late spring to midsummer. The fruits are small, spherical green or brown achenes that provide food for waterfowl and other wildlife.

In cultivation, Sparganium natans is valued for its ability to naturalize in water gardens and provide habitat for aquatic organisms. It is often used in constructed wetlands for water purification purposes. The plant prefers full sun to part shade and requires standing water or wet, muddy substrates to thrive. While it is generally low-maintenance, it can spread vigorously in ideal conditions, potentially becoming invasive in some areas. Gardeners should monitor its growth to prevent unwanted spread.CC BY-SA 4.0