Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Russian knapweed, Extension, University of Nevada, Reno, Field Guide

Stem

  • Numerous; highly branched, stiff, 1-3 ft. tall and covered with wooly gray hair; NO wings
Photo of russian knapweed

Leaves

  • Alternate; mostly covered with wooly gray hair 
  • Lower leaves 2-4 in. long with lobed to wavy edges (margins); upper leaves strap-like (linear) or lance-shaped and less than 1.2 in. long with smooth or toothed edges
Photo of Russian knapweed

Flower

  • Purple, pink or white, each located at the tip of a branch; base of flower is vase-shaped, 0.25-0.5 in. wide and covered with green bracts with papery or whitish edges
Photo of Russian knapweed

Root

  • Creeping root system; upper roots often dark brown to black
 

Other

  • Grows well on a broad range of sites; often found in rangeland, waste areas, roadsides and along waterways; known to occur throughout Nevada
  • Perennial; reproduces by roots and seed
  • Causes “chewing disease” in horses by damaging the area of the brain that controls fine motor movements, particularly of the mouth; results in starvation or dehydration
 

Control

  • Mowing and tillage are NOT effective
  • Apply aminocyclopyrachlor, chlorsulfuron or clopyralid from the bud to flower stage; aminopyralid or picloram from bud through dormancy; imazapic to dormant plants in fall

Learn more about the author(s)

Gary McCuin
Gary McCuin
 

Also of Interest:

 
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This carcass of merit program, utilizing a grid pricing system, recognize harvested animals with carcass traits that would be of similar economic value if they were sold on the open market.
 Suverly, N. and Torell, R. 2004, Extension | University of Nevada, Reno, FS-04-03
Nevada Market Lamb Carcass Merit Program
This carcass of merit program, utilizing a grid pricing system, recognizes harvested animals with carcass traits that would be of similar economic value if they were sold on the open market.
 Torell, R. 2004, Extension | University of Nevada, Reno, FS-04-02