APHIS (Animal and Plant Health Inspection Service, USDA) California Department of Pesticide Regulation Canadian Poisonous Plants Information System 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 National Institute of Food and Agriculture, USDA (formerly CSREES) Plants Database, USDA-NRCS USDA USDA-ARS