Also known as: Eggleaf spurge, Balkan spurge
Oblong spurge is commonly planted in gardens as an ornamental species – with brilliantly bright yellow flowers, it’s no wonder why! However, it doesn’t remain an ornamental for long. Its seed capsules can eject seeds up to six feet away! Once established, it spreads quickly through natural areas and along waterways.
CAUTION: Avoid handling this plant, it is toxic! Its stems contain a milky sap that irritates skin upon contact.
Description:
Life Cycle: | Perennial (life cycle lasts more than one year) |
Early Detection and Rapid Response species: | Yes |
Height: | 3 feet (1 meter) |
Leaf Description: | Light green, egg-shaped leaves have finely toothed edges. Its stems contain a milky, latex sap that can cause skin irritation. This sap is toxic to humans and livestock when consumed. |
Fruit & Flower Description: | Small, yellow flowers grow in clusters surrounded by yellow-green bracts Small leaf-like structures that are just below a plant’s flower.. Three smooth, brown seeds are held in oval seed capsules. When ripe, seeds are ejected several feet. |
Bloom Time: | March to August |
Habitat:
- This hardy species can grow in a variety of habitats but prefers moist soil conditions along streams, in wet meadows, and shady woodlands.
- Prefers partial shade to full sun.
Impact:
- Can from dense stands that create a monoculture Growing a single crop or plant., outcompeting native plant species.
- Its toxic sap causes skin and eye irritation if handled without proper protection. It can also cause internal soft tissue issues in livestock when ingested.
- Because of its toxicity, infestations offer no resources to wildlife. It only displaces native plant species that wildlife use for food and habitat.
What we’re doing about it:
- Oblong spurge is a priority species for the Tualatin SWCD. As such, our Invasive Species Program has been actively monitoring and treating it throughout the watershed.
- If identified within Washington County, a specially trained crew can come out and survey for it. If found, the crew will treat the infestation for free.
What you can do about it:
- Please report any oblong spurge infestations to the Oregon Invasive Species Hotline.
- Do not mow oblong spurge as this will only spread it to new locations.
- Hand pulling small infestations can be effective. Spring is the best time to remove it—when the soil is damp and before it has gone to seed.
- Make sure to remove the entire root system and throw away the plant in a plastic bag in the trash— not your yard waste bin or home compost.
Look-alikes:

Leafy spurge (Euphorbia esula), another invasive species, looks similar to oblong spurge. Leafy spurge’s leaves are longer and thinner than oblong spurge’s leaves. They also grow closer to the stem.
Noxious Weed Listing:
State of Oregon: | Class A, T |
State of Washington: | Class A |
More Resources:
Download the Oblong Spurge Best Management Practices Factsheet
- Pacific Northwest Weed Management Handbook: Oblong or eggleaf spurge
- University of California, Weed Research & Information Center: Oblong spurge