Free plant identification application determines plant and tree species through leaf photographs.

Easy-to-use tree identification online tool. Identifies a tree by searching for attributes and common names in a number of languages.

Simplified guide to identifying fifty common Native North American trees. Also offers a beginner tree identification e-course.

Definition of a tree and details on identifying trees through a number of means. Also includes information on tree evolution, benefits, and problems.

Database on identifying woody landscape plants. Includes data on native and introduced species.