Description:

Oblong spurge is an escaped ornamental in the Euphorbiaceae (Euphorbia) family. It has a branching stem that produces up to 20 stems from a woody rootstallk. The leaves are alternate, hairless,finely toothed, somewhat oblong and egg-shaped, and up to 2.6 inches long. The flowers are very small and yellow, and they grow in clusters surrounded by yellow-ish green bracts and leaves. The stems contain a milky, latex sap that can cause skin irritation. The seeds have a sticky coating and can eject several feet. The plant spreads mostly by seed, but also through root fragments.

Life cycle:

Perennial

Height of mature plants

3 feet

Flower color:

Yellow

Bloom time:

March – August

Look-a-likes:

Oblong spurge looks similar to other Euphorbia species, especially leafy spurge (Euphorbia esula) whose leaves are more narrow.

Habitat:

Oblong spurge does best in moist soil conditions, but can grow in a wide variety of habitats including damp meadows, pastures, stream banks, shady woodlands, roadsides, and disturbed areas.

Impacts:

Oblong spurge can form dense stands that out-compete native plants, thus reducing plant diversity and habitat. The stems also contain a toxic milky sap that can irritate skin and internal soft tissues of livestock when ingested.

Noxious Weed Listing:

• WeedWise: priority
• State of Oregon: Class A, T
• State of Washington: Class A
• Four County CWMA: Class A
• Columbia Gorge CWMA: Class A

Origin:

Southeast and Mediterranean Europe

Links:

Oregon Noxious Weed Profile
Washington Noxious Weed Profile
California Invasive Plant Council Profile
CABI Invasive Species Compendium