Photographer: Norman E. Rees Affiliation: USDA Agricultural Research Service - Retired Source: Bugwood.org Copyright: (CC BY 3.0)
Leafy spurge (Euphorbia esula) is a leafy herb that can grow up to 3.5 feet, with yellow flower bracts, and small oval shaped leaves with a frosted appearance at the margin. The roots extend several feet under ground, with cases of 15 feet of extension underground, and stems above ground in clusters. Yellow flower bracts appear on leafy spurge in May, but the small yellow green flowers do not appear until June.
Leafy spurge is an aggressive plant that rapidly takes over open areas by out-competing native plant species. The ability to grow taller than many native plants allows leafy spurge to prevent sunlight from reaching shorter plants. Leafy spurge also secrets a toxin, further preventing growth of native plants.
Leafy spurge has a high germination rate via explosive seed release that allows seeds to be spread up to 15 feet from the parent with additional distance aided by wind. In addition to seed germination, the leafy spurge is able to spread vegetatively with root systems increasing by several feet each year.
Leafy spurge was accidentally introduced to the United States in the 1800's as a contaminant in seeds. The first record in the United States was in 1827 in Massachusetts.
Eurasia
Habitat: With a preference for dry conditions, the leafy spurge thrives in areas that allow it to out-compete native plants for limited water resources. In the United States leafy spurge is often found in disturbed areas, road sides, abandoned fields, prairies, savannas, and pastures.
Distribution
U.S. Present: CA, CO, CT, IA, ID, MI, MN, MT, NC, ND, NE, NJ, NM, OR, SD, UT, VA, WA, WI, WY
For a map of distribution, survey and eradication efforts click here.
Once established, the leafy spurge is very difficult to eradicate due to an extensive root system and rapid seed germination. Some management techniques such as fire and chemical treatments have been proven effective in removing leafy spurge infestations when applied properly. Chemical treatments can also be effective when applied in June or in mid-early September. This timing allows for treatment when the plant is transporting nutrients and creates maximum uptake potential of pesticides.
Text References
Lacey, C. A., R. W. Kott, and P.K. Fay. 1984. Ranchers control leafy spurge. Rangelands 6(5): 202-204.
Lym, R. G., C. G. Messersmith, and R. Zollinger. 1993. Leafy spurge identification and control. Report W-765. North Dakota State University Extension Service, NDSU, Fargo.
Sun, M. 1981. The purge of leafy spurge. Science 214: 1103.
Wolters, G. L., C.H. Sieg, A. J. Bjugstad, and F. R. Gartner, 1994. Herbicide and fire effects on leafy spurge density and seed germination. Research Note RM-526. Rocky Mountain Forest and Range Experiment Station, U.S.D.A. Forest Service.
Internet Sources
http://www.invasivespeciesinfo.gov
http://www.nps.gov/plants
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