- Australian National Botanic Gardens–Plant Science
Plant Science site from the Australian National Botanic Gardens
- Lady Bird Johnson Wildflower Center
A collection of over 16,900 plant images representing 176 Plant Families and 4,443 individual species. Searches possible.
- Texas Plant Disease Handbook
Site from Texas A&M University Department of Plant Pathology and Microbiology. It provides information on various plant diseases and control.