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Water primrose identification and control: Ludwigia hexapetala

Water primrose identification and control

Ludwigia hexapetala

water primrose flowers and leaves
This aquatic Class B noxious weed has been observed occasionally in King County, Washington. The largest infestations of water primrose in the state are in southwest Washington where there are extensive mats of this weed along channels in the lower Columbia River area. Control 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 on noxious weed regulations and definitions, see Noxious weed lists and laws.

Additional information on water primrose

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

Please notify us if you see water primrose 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 water primrose 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 water primrose in order to help us and others locate new infestations in time to control them.

Water primrose photos

Water primrose (small)
Water primrose (small)

Report water primrose in King County, Washington

Locate water primrose in King County, Washington

Related information

Related agencies

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).