Leafy Spurge
Euphorbia virgata
Washington State Classification
Class B — Control Required (Designated)
It is toxic to some animals and reduces the livestock carrying capacity of pasture and rangeland by 20 to 50%, causing an estimated $35-45 million loss per year in US beef and hay production in addition to the millions of dollars spent for control.
Required control in Region 1 (all western Washington counties)
Quick Reference
Identification
Growth Habit
It is a perennial, rhizomatous plant with stems which originate from a crown just below the soil surface. The plants begin growing in early spring before their competitors. Stems, roots and leaves exude a milky sap that can be an irritant to skin.
Leaves
Leaves are alternate, narrow and about 3 inches long with lowest leaves much reduced. Leaves have smooth margins and may have a whitish coating. Leaves by flowers are broad, heart-shaped and yellow-green, turning red in the fall after the first frost.
Flowers
Clusters of small, greenish flowers at the tips of branches made up of many male flowers and one female flower. Yellow bracts occur at the base of flower cluster, may appear to be petals from a distance.
Fruit & Seeds
Capsule with seeds inside fairly smooth and dividing into 3, 1-seeded pieces.
Impact
It is toxic to some animals and reduces the livestock carrying capacity of pasture and rangeland by 20 to 50%, causing an estimated $35-45 million loss per year in US beef and hay production in addition to the millions of dollars spent for control.
Ecology & Spread
Habitat
Leafy spurge can adapt to a wide range of habitats. It spreads rapidly in areas where cattle or other grass grazing animals remove competing plants. Habitats include cropland, pastures, rangeland, urban parks, roadsides and disturbed sites. Please click here to see a county level distribution map of leafy spurge in Washington.
Spread Mechanisms
Reproduction
Leafy spurge reproduces by seed and vegetatively from its root crown and root buds.
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Control Methods
Mechanical
- Gloves and protective clothing are needed when handling leafy spurge to avoid contact with milky sap. Hand pulling leafy spurge is difficult due to its extensive root system. Plants can be mowed to prevent seed production but the roots can still spread.
Biological Control
- There are a number of biological control agents used to control leafy spurge. Leafy spurge flea beetles, Apthona spp., adults and larvae attack leaf spurge by feeding on leaves and flowers (adults) and on root hairs and young roots (larvae). The red-headed leafy spurge stem borer, Oberea erythrocephala, have larvae that feed within the stems and root crowns and the adults cause secondary damage by chewing around (girdling) stems and causing stem death. The leafy spruge tip gall midge, Spurgia esulae, have larvae that feed and form galls on young stem tips. The galling and feeding by the larvae suppress floweirng and seed production. For more information about these biological control agents of leafy spurge, please visit WSU Extension Integrated Weed Control Project. Goats have also been used for the selective grazing of leafy spurge.