Bayer Codes for Pests - NSF Center for Integrated Pest Management

http://www.cipm.info/names/index.cfm

ITIS - Integrated Taxonomic Information System

http://www.itis.gov/index.html

Natural Resources Conservation Service Plants Database - USDA

http://plants.usda.gov/index.html

WISFLORA: Wisconsin Vascluar Plant Species - Wisconsin State Herbariium

http://www.botany.wisc.edu/wisflora/