Fanwort (Cabomba caroliniana) is a submerged aquatic plant native to South America. Its name is derived from the fan-like appearance of its foliage.
Fanwort has been found in the Hudson Basin, the Catskills, and Long Island. Fanwort has also been identified in Kasoag Lake in Oswego County.
Fanwort has the ability to overwinter and grow rapidly in the spring and summer, outcompeting and dominating the native vegetation. Fanwort’s dense foliage reduces light availability for benthic organisms and native plants. This results in a decline in populations of fish and other animals dependent on these native organisms. Dissolved oxygen is also depleted as fanwort decays in autumn, causing a reduction in animal populations. Below is a photo that shows how thick fanwort masses can become.
Leaves are submerged, opposite and feathery and are “Y-shaped” at the end, often referred to look like a snakes tongue.
Stems are slender and commonly grow between 3-4 feet long.
Flowers have six white petals with yellow stamens
Fanwort can be controlled using chemical treatment, mechanical and manual harvesting, water level manipulation, and benthic barriers. However, these methods have had limited success or have high fiscal and ecological costs.
Fanwort is easily spread by plant fragmentation. Be sure to Clean, Drain, Dry your watercraft and equipment, and avoid driving watercraft through established fanwort colonies.
Fanwort title photo, infestation photo, and flower by Leslie J. Mehrhoff, invasive.org
Fanwort leaf with flower by Graves Lovell, Bugwood.org.