ARS | Publication request: Larkspur - Poison Weed (100 Years of Delphinium Research)

Submitted to: Rangelands
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 7, 2009
Publication Date: February 1, 2009
Repository URL: http://www.pprl.ars.usd.gov
Citation: Green, B.T., Gardner, D.R., Pfister, J.A., Cook, D. 2009. Larkspur - Poison Weed (100 Years of Delphinium Research). Rangelands, 31(1):22-27. http://www.bioone.org/doi/pdf/10.2111/1551-501X-31.1.45?

Interpretive Summary: Delphiniums (larkspur) are members of the Ranunculacae family of plants which are commonly known as the Buttercup family. Toxic Delphinium spp., or more commonly known as larkspur are found in the foothill and mountain rangelands of the western United States. Although the scope of the problem caused by toxic larkspur varies from year to year, the overall losses due to larkspur have remained remarkably consistent over time. There are three basic categories of larkspur, plains, low, and tall based upon mature plant height, and geographic distribution. All contain toxins that when consumed in sufficient amounts by cattle will cause bloating, respiratory depression, and death. Management options for the control of larkspur poisoning in cattle include herbicide control, grazing strategies, food aversion, grazing sheep before cattle, and drug therapy for poisoned animals.

Technical Abstract: Larkspurs (Delphinium spp.) are found in the foothill and mountain rangelands of the western United States. Losses to ranchers from larkspurs range from 2 to 5 percent and as high as 15% in places with large stands of toxic larkspur. There are three basic categories of larkspur, plains, low, and tall based upon mature plant height, and geographic distribution. All contain toxins that when consumed in sufficient amounts by cattle will cause bloating, respiratory depression, and death. Management options for the control of larkspur poisoning in cattle include herbicide control, grazing strategies, food aversion, grazing sheep before cattle, and drug therapy for poisoned animals.