This noxious weed is a submersed, floating (often rooted) perennial. It is a Class B noxious weed and has very limited in distribution in Washington State. Detection and eradication of new sites is a high priority statewide. There are no known populations in King County, so it is very important to report any sightings of this plant, especially in natural water bodies or waterways. Control of fanwort is required in King County. This species is also on the Washington quarantine list (known as the prohibited plants list) and it is prohibited to transport, buy, sell, offer for sale, or to distribute plants or plant parts of this species, into or within the state of Washington. It is further prohibited to intentionally transplant wild plants and/or plant parts of this species within the state of Washington. For more information see Noxious weed lists and laws.

Additional information on fanwort

• Washington State Noxious Weed Control Board (external link)

What to do if you find this plant in King County, Washington

Please notify us if you see fanwort growing in King County. Our program staff can provide the property owner or appropriate public agency with site-specific advice on how best to remove it. Also, because fanwort is not established in King County, we have an opportunity to stop it from spreading if we act quickly. We map all known locations of regulated noxious weeds such as fanwort in order to help us and others locate new infestations in time to control them.

Report fanwort in King County, Washington

• Please notify us through our online infestation form

Locate fanwort in King County, Washington

• Use our interactive noxious weed map and search for fanwort

Related information

• Lakes
• Northwest yard and garden
• Animals, plants and habitat
• Wetland topics

Related agencies

• Dept. of Natural Resources and Parks
• Water and Land Resources Division

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Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. To contact staff, see the Noxious Weed Control Program Directory, send an email, or call 206-477-WEED (206-477-9333).