Plants poisonous to livestock, pets and humans in Canada. Also has links to other poisonous plant resources.

From the US Army Center for Health Promotion and Preventive Medicine.

Directory of toxic plants and herbs and their effects.

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.

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]