Fennel pondweed (Stuckenia pectinata), also known as sago pondweed, is a native aquatic plant commonly found in ponds, lakes, rivers, canals, and slow-moving waterways throughout Europe, Asia, North America, and beyond. It is characterized by its long, slender, thread-like leaves that resemble fennel foliage, giving the plant its common name.
This hardy species thrives in a wide range of water conditions, including brackish and nutrient-rich waters. It plays an important ecological role by providing shelter and spawning habitat for fish, refuge for aquatic invertebrates, and food for waterfowl, particularly ducks and swans, which feed on its seeds and tubers.
Fennel pondweed can form dense underwater beds that help stabilize sediments, improve water clarity, and support biodiversity