Leafy spurge flowers and leaves

Leafy spurge (Euphorbia esula)

Herbaceous perennial with deep root systems and milky sap in stems, flowers, and leaves. Sap is distasteful to some animals and can cause blistering on their mouths or throats. Leafy spurge grows to be 2-3’ tall.

Overview

Regulated areas of leafy spurge
Leafy spurge is Restricted (Orange counties)

Other names for this plant include:

  • Common names: spurge, wolf's milk
  • Scientific names: E. esula ssp. esula; E. esula var. esula

Ecological threat:

  • Invade open areas, including prairies, savannas, and roadsides. Can quickly create monocultures, excluding native vegetation and reducing wildlife habitat value.
  • Tolerant of a wide range of habitats, from dry to moist and sunny to semi-shade. Most aggressive in areas where soil moisture is limited.

Classification in Wisconsin: Restricted

Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for leafy spurge was based upon this literature review developed by the department.

Identification

Leaves: Leaves are simple, alternate, bluish-green, smooth, and hairless with pointed tips.

Flowers: Small, yellowish-green, and surrounded by cup-shaped bracts. Flowers are paired, with 7-10 pairs clustered in umbels at tops of stems. Bloom late spring through mid-summer.

Fruits & seeds: Capsules contain 3 seeds each and burst when dry, dispersing seeds explosively. Each plant can produce more than 250 seeds. Seeds remain viable in the soil for up to 8 years. Dispersed by wildlife, humans, and water.

Roots: Extensive root system with taproots extending up to 15’ deep and lateral roots spreading up to 35’. New sprouts from root buds facilitate spread into undisturbed areas.

Distribution

Known county distribution of leafy spurge
Counties in WI where leafy spurge has been reported (as of July 2011). Both vouchered and unvouchered reports included.

Do you have leafy spurge in your county but it isn't shaded on the map? Send us a report.

Control

Mechanical: Hand pulling or digging is only effective if entire root system is removed.

Chemical: Aminopyralid is effective for spot treatments. Imazapic with methylated seed oil (MSO) is recommended for fall applications.

Biological: Stem and root boring beetle, four root-mining flea beetles, and a shoot-tip gall midge.

For more information on control techniques, visit the Leafy spurge factsheet [exit DNR] by University of Wisconsin-Extension.

Photos

View leafy spurge pictures in our photo gallery!

Resources

Sources for content:

  • Czarapata, Elizabeth; Invasive Plants of the Upper Midwest: an illustrated guide to their identification and control. University of Wisconsin Press. 2005.
  • Center for Invasive Species and Ecosystem Health, Invasive.org. Last updated on Sunday, March 08, 2009. Leafy spurge [exit DNR]
  • Invasive Plant Atlas of New England: Euphorbia esula [exit DNR]
  • USDA Forest Service, Northeastern Area Forest Health Staff. Weed of the Week: Leafy Spurge [exit DNR]

Links for More Information

Last revised: Tuesday June 04 2013