Amaranthus palmeri S.Watson (ITIS)
Palmer amaranth, palmer pigweed, carelessweed
Southwestern U.S. (Ward et al. 2013)
Most likely through the transport of contaminated seed; some recent infestations in the Midwest were caused by contaminated Conservation Reserve Program seeding mixes (Ward et al. 2013; Murphy et al. 2017)
One of the most economically important weeds of corn, cotton, and soybean; some populations are resistant to glyphosate and other herbicides (Ward et al. 2013)
United States Department of Agriculture. USDA Climate Hubs.
Palmer amaranth (Amaranthus palmeri S. Watson) is an annual plant in the pigweed family (Amaranthaceae). It is native to the southwest United States/northern Mexico deserts and is currently increasing its range across the country. USDA NRCS, their partners, as well as farmers and landowners are working to eradicate these infestations before they spread to new areas. Midwest Climate Hub fellow, Dr. Erica Kistner-Thomas is getting a jump on how the distribution of Palmer amaranth will change from current to future climate conditions. Climate change is going to benefit this heat-tolerant weed by lengthening its growing season, boosting seed production and expanding its potential U.S. geographic range.
Distribution / Maps / Survey Status
The section below contains highly relevant resources for this species, organized by source. Or, to display all related content view all resources for Palmer Amaranth.
European and Mediterranean Plant Protection Organization.
North Central Integrated Pest Management Center.
See also: Pest Alerts for more resources
United Soybean Board.
USDA. ARS. National Genetic Resources Program. GRIN-Global.
State and Local Government
University of Florida. Institute of Food and Agricultural Sciences Extension.
Electronic Data Information Source Publication #SS-AGR-336
University of Delaware. Cooperative Extension.
See also: Weed Management Guides for more resources
University of Maryland Extension.
See also: Invasive Plants for more resources
Purdue University Extension.
Iowa State University. Extension and Outreach. Integrated Crop Management.
University of Minnesota Extension.
Culpepper, A.S., T.L. Grey, W.K. Vencill, et al. 2006. Glyphosate-resistant Palmer amaranth (Amaranthus palmeri) confirmed in Georgia. Weed Science 54(4):620-626.
Integrated Taxonomic Information System. Amaranthus palmeri. [Accessed Apr 20, 2019].
Murphy, B.P., D.E. Plewa, E. Phillippi, et al. 2017. A quantitative assay for Amaranthus palmeri identification. Pest Management Science 73(11):2221-2224.
Ward, S.M., T.M. Webster, and L.E. Steckel. 2013. Palmer amaranth (Amaranthus palmeri): a review. Weed Technology 27(1):12-27.