Broom snakeweed is a native weed widely distributed on rangelands of western North America. It often increases to near monocultures following disturbance from overgrazing, fire, or drought. This paper presents an up-to-date review of broom snakeweed toxicology, seed ecology, population cycles, succession, and management. The greatest ecological concern is that broom snakeweed displaces desirable forage for livestock or wildlife and greatly reduces biodiversity. It also is toxic and can cause abortions in all species of livestock. Propagation usually is pulse-driven in wet years, allowing large expanses of even-aged stands to establish and dominate plant communities. Snakeweed can be controlled by prescribed burning or spraying with herbicides. A weed-resistant plant community dominated by competitive grasses can prevent or minimize its reinvasion.

Nomenclature: Broom snakeweed, Gutierrezia sarothrae (Pursh) Britton & Rusby GUESA

Interpretive Summary: Broom snakeweed is an invasive native subshrub that is distributed widely across rangelands of western North America. In addition to its invasive nature, it contains toxins that can cause death and abortions in livestock. It establishes in years of above-average precipitation following disturbance by fire, drought, or overgrazing. This allows widespread, even-aged stands to develop that can dominate plant communities. Although its populations cycle with climatic patterns, it can be a major factor impeding succession of plant communities. Snakeweed can be controlled with prescribed burning and herbicides; however, a weed-resistant plant community should be established and/or maintained to prevent its reinvasion. Proper grazing management to maintain competitive grasses is essential for suppression of this invasive weed.