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BLM
U.S. DEPARTMENT OF THE INTERIOR
BUREAU OF LAND MANAGEMENT
Spotted knapweed. Salt cedar. Leafy spurge. Musk thistle. Dalmation toadflax.
Wyoming
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Leafy Spurge

 

Leafy Spurge closeup.

 

Leafy Spurge closeup.


 

Field of Leafy Spurge.

 

Leafy Spurge.

Interesting Facts

  • Milky latex can cause irritation, blotching, blisters, and swelling
  • The plant produces a compound that inhibits the growth of other plants
  • Poisonous to some grazing animals
  • Roots can extend down 15 feet
  • Seed capsules open explosively, dispersing seed up to 15 feet

Description
A stout, erect perennial forb in the spurge family

  • Stems are upright, grayish, and can grow to 2 to 3 feet tall.
  • Leaves are small, oval to lance-shaped, somewhat frosted and slightly wavy along the margin
  • Flowers are very small and are borne in distinctive greenish yellow structures surrounded by yellow bracts.
  • Seed/Fruit are oblong, greyish to purple, contained in a 3-celled capsule.

Habitat
Leafy spurge tolerates moist to dry soil conditions but is most aggressive under dry conditions where competition from native plants is reduced. It is capable of invading disturbed sites, including prairies, pastures, abandoned fields and roadside areas.

Ecological Impacts
Leafy spurge displaces native vegetation in prairie habitats and fields through shading and by utilizing available water and nutrients and through plant toxins that prevent the growth of other plants underneath it. Leafy spurge is an aggressive invader that can completely overtake large areas of open land.

Control

Mechanical:  Tillage, mowing, and pulling are generally ineffective control treatments because of the plant’s extensive root system.
 
Chemical:  It can be effectively controlled using any of several readily available general use herbicides such as glyphosate or a restricted-use herbicide, picloram. It is best to apply in June, when the flowers and seeds are developing, or in early to mid-September, when the plants are moving nutrients downward into the roots. Being a restricted-use herbicide, Picloram should only be applied by a state certified applicator. Contact your local county weed and pest office for more information.
 
Biological:  The U.S. Department of Agriculture has shown success using six natural enemies of leafy spurge imported from Europe. These include a stem and root - boring beetle (Oberea erythrocephala), four root-mining flea beetles (Aphthona spp.) and a shoot-tip gall midge (Spurgia esulae). Large scale field-rearing and release programs are carried out cooperatively by federal and State officials. The results are not as immediate as when herbicides are used but, if pesticide use is kept to a minimum, large numbers of these agents build up within a few years and have shown impressive results.