Eggleaf Spurge
Euphorbia oblongata
Washington State Classification
Class A — Eradication Required Statewide
It was introduced as a garden ornamental and escaped cultivation.
Quick Reference
Identification
Growth Habit
It is an upright perennial reaching to about three feet tall from a woody, branched taproot. Plant stems covered in fine white hairs and have leaves with finely toothed margins. Flowers bloom in spring and summer.
Leaves
The leaves are alternate, hairless and oblong with finely toothed margins. Leaves have a prominent midvein. They grow to about 2.6 inches long.
Flowers
Flowers in clusters made up of small male flowers and one small female flower. Flower clusters have yellow bracts at their base followed by a whorl of yellowish green leaves.
Fruit & Seeds
Seeds are held in three lobed capsules. Seeds are brown and smooth and are ejected from capsules when ripe.
Impact
It was introduced as a garden ornamental and escaped cultivation. It’s closely related to, and exhibits invasive and competitive strategies similar to, leafy spurge (Euphorbia virgata) which is listed as a Washington State Class B noxious weed.
Ecology & Spread
Habitat
It is found in damp meadows, streambanks, shady woodlands as well as on dry hillsides, roadsides and waste areas. Please click here to see a county level distribution map of eggleaf spurge in Washington.
Spread Mechanisms
Reproduction
Eggleaf spurge reproduces by seed and can grow from buds from the root crown, which can produce new stems or roots.
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Control Methods
Mechanical
- Because of large taproot, the plant must be dug. Mowing will result in new shoots growing. Eggleaf spurge produces a milky latex sap so care should be taken when handling. If sap contacts skin make sure to wash that area.