Leafy spurge identification and control
Introduced from Eurasia, leafy spurge now dominates large areas in the northern Great Plains. When the plant is cut or torn a milky latex flows that can produce blisters on humans and cattle, as well as irritation of the mouth and digestive tract. Leafy spurge causes scours and weakness in cattle and may kill them; however, sheep and goats can graze it.
Legal status in King County, Washington
Leafy spurge is a Class B Noxious Weed in Washington and property owners in King County are required to control it if it occurs on their property. 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, seeds in packets, blends or "wildflower mixes" of this species, into or within the state of Washington. For more information on noxious weed regulations, see Noxious weed lists and laws.
Biology and morphology
Leafy spurge is a long-lived perennial with a deep, extensive, creeping root system. Dense infestations form when numerous systems grow from buds below the soil surface. Stems grow 1 to 3 feet tall with linear, alternate bluish-green leaves. Flowers are borne in an umbel and are surrounded by yellowish-green showy bracts. Flowering stalks produce 10 to 50 seed capsules, each containing 3 seeds. When dry, the capsules explode to eject the seeds as far as 15 feet away from the parent plant. Although it often invades moist places first, it is well adapted to dry upland sides and rocky, shallow soils.
Additional information on leafy spurge
- 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 leafy spurge 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. We map all known locations of regulated noxious weeds such as leafy spurge in order to help us and others locate new infestations in time to control them.
Report leafy spurge in King County, Washington
- Please notify us through our online infestation form
Locate leafy spurge in King County, Washington
- Use our interactive noxious weed map and search for leafy spurge