Click on the icon for access information. Comprehensive Keys - These guides cover many genera such as regional tree keys or a 'campus flora'. All Families - World Wide Flora Plant Family ID by Dr. Ray Phillips of Colby College. No matter how many or few characters you have available it will suggest family matches. Interactive Key of Common Iowa Trees from Iowa State University.
Photographs assist each choice.
Detailed illustrations and descriptions are quite useful. Ohio Historical Society Key provides leaf and fruit keys. Users click on images that match their specimen. European Garden Flora - this published set of encyclopedias provide the most complete set of keys to cultivated species ever offered. It is work of vast scope and was compiled by finest European taxonomists.