• APHIS (Animal and Plant Health Inspection Service, USDA)
  • California Department of Pesticide Regulation
  • Canadian Poisonous Plants Information System
  • CSREES (Cooperative State Research, Education, and Extension Service, USDA)
  • EPA Pesticide Topics
  • Federal Interagency Committee for the Management of Noxious & Exotic Weeds, USDA
  • IR-4 Project
  • National Agricultural Library, USDA
  • National Agricultural Statistics Service, USDA
  • Plants Database, USDA-NRCS
  • USDA
  • USDA-ARS