Canadian Poisonous Plants Information System
   Plants poisonous to livestock, pets and humans in Canada. Also has links to other poisonous plant resources.
   http://www.cbif.gc.ca/pls/pp/poison

Cornell University Poisonous Plants
   Searchable database of plants toxic to humans and animals.
   http://www.ansci.cornell.edu/plants/index.html

Guide to Poisonous Plants
   Searchable database from the Colorado State College of Veterinary Medicine and Biomedical Sciences.
   http://www.vth.colostate.edu/poisonous_plants/

Guide to Poisonous and Toxic Plants
   From the US Army Center for Health Promotion and Preventive Medicine.
   http://chppm-www.apgea.army.mil/ento/PLANT.HTM

Index of Poisionous Plants
   Directory of toxic plants and herbs and their effects.
   http://www.botanical.com/botanical/mgmh/poison.html

Poisonous Plant Database
   A listing of papers of scientific information about the animal and human toxicology of vascular plants of the world. From the U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition.
   http://www.cfsan.fda.gov/~djw/plantox.html

The Poisonous Plant Patch
   Detailed information on several species of poisonous plants. Photographs, plant toxins, medicinal or toxic and an illustrated guide to poisonous plants in Nova Scotia. [Many of these are not regional specific - ed]
   http://museum.gov.ns.ca/poison/pplant1.htm