References Sources used for gathering information and photographs:
Tri-County CWMA (tricountycwma.org) located at 10507 N. McAlister Rd. La Grande, Oregon.
Oregon Department of Agriculture, (2019). ODA Plant Division, Noxious Weed Control. Retrieved from State of Oregon: ODA Plant Division, Noxious Weed Control Web site: http://www.oregon.gov/ODA/PLANT/WEEDS/
Union County Weed Control Board, (2019). Union County Weed Management Plan. La Grande: Union County Weed Department.
Western Society of Weed Science, (2017). Western Society of Weed Science. Retrieved from Western Society of Weed Science Web site: http://www.wsweedscience.org/
Whitson, T, & et. al., (1992). Weeds of the West. Western Society of Weed Science in cooperation with the Western United States Land Grant University Cooperative Extension Service.
Cronquist, A., and C.L. Hitchcock (1973). Flora of the Pacific Northwest: An Illustrated Manual. Seattle, WA: University of Washington Press.
British Columbia Ministry of Agricultural Lands, (2007). Field Guide to Noxious and Other Selected Weeds of British Columbia. Retrieved from the ministry of Agricultural Lands Pest Management Web site:http://www.agf.gov.bc.ca/cropprot/weedguid/weedguid.htm
National Jointed Goatgrass Research Program, (2007). Jointed Goatgrass Management. Retrieved from The National Jointed Goatgrass Research Program Web site: http://www.jointedgoatgrass.org/welcome.htm
Washington State Noxious Weed Control Board, (2007). Washington State Noxious Weed Control Board. Retrieved from The Washington State Noxious Weed Control Board Web site: http://www.nwcb.wa.gov/
University of California Integrated Pest Management, (2007). UC Statewide Integrated Pest Management Program. Retrieved from UC-IPM Web site: http://www.ipm.ucdavis.edu/index.html