Broom Snakeweed (Gutierrezia sarothrae)
Livestock producers lose thousands of dollars each year that can be attributed to animals ingesting toxic plants. The best way to prevent these losses is by recognizing harmful species in the areas where they grow and thrive. Perhaps the easiest prevention is to manage grazing lands to provide adequate and palatable forage for grazing animals.
Broom snakeweed is a short-lived perennial half-shrub found throughout Texas and the western United States.
- Has narrow, threadlike leaves and many unbranded stems sprouting from a woody base
- From June to October, small yellow flowers form at the tips of the branches
- Can reach a height of 6 inches to 2 feet tall
- Found on arid rangelands in the western U.S. and Mexico
Broom snakeweed can severely reduce forage production on grazing lands but does not necessarily indicate overgrazing. Populations are influenced by climate and growing conditions each year, but severe grazing can influence plant populations by reducing natural competition between grasses and the snakeweed.
Broom snakeweed contains a compound called saponin, which poisons grazing animals. The plant seems to be the most toxic in early spring and late winter on sandy-textured soils; it has not shown toxic properties on clay soils. The plant causes abortions in cattle that consume as little as 20 pounds in a week’s grazing. Consumption equal to 10 to 20 percent of an animal’s body weight in a period of 14 days is usually deadly.
Avoid grazing sandy areas that are infested with the plant during late winter and early spring. Good grazing management can improve grazing conditions and reduce plant populations. The plant can be controlled by properly timed applications of herbicides if it becomes dense and impedes forage production.
Editor’s note: Kent Ferguson, retired rangeland management specialist from USDA Natural Resources Conservation Service (NRCS), is providing us with plant identification photo stories to help ranchers identify those forbs, forages and species growing in the pastures. Additional photos provided by USDA NRCS.
Broom Snakeweed is excerpted from the February 2017 issue of The Cattleman magazine.