Cornell University Poisonous Plants Page
This is a rapidly growing reference that includes plant images, pictures of affected animals and presentations concerning the botany, chemistry, toxicology, diagnosis and prevention of poisoning of animals by plants and other natural flora (fungi, etc.). When completed, the public will be able to find pictures and information about: toxic plants, conditions of poisoning, general information on controlling the growth of the plant, and symptoms animals display from poisoning. You can also link to other Veterinary Schools from their web site.

Canadian plants poisonous to dogs from the Canadian Poisonous Plants
Information System.

Plants Toxic to Animals
by M. Williams, Veterinary Medicine Librarian, University of Illinois at Urbana-Champaign. This list was created in order to assist the University of Illinois veterinary students in identifying common plants that are toxic to animals. Plant entries can be selected from either the common name list or the scientific name list of plants. Has great color photos of plants.

Poisonous Plants by D. Hall, Florida Agricultural Information Retrieval System (FAIRS), University of Florida. A multimedia database (text and images), including Poisoning Symptoms and Possible Causal Plants, and a Poisonous Plants Glossary.