History and Impact
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. As a Class B noxious weed, its control is required in King County.

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.

For more information about leafy spurge, please follow this link to the WA State Noxious Weed Control Board.

If you find leafy spurge in King County, please notify us through our online infestation form.

To find out where we have records of this weed in King County, use our interactive noxious weed map and search for leafy spurge.