Columbia University, the University of Maryland, and the Smithsonian Institution are working on visual recognition software to help identify species from photographs. Leafsnap is the first in a series of electronic field guides being developed to demonstrate this new technology.
This free mobile app helps identify tree species from photographs of their leaves. Leafsnap currently includes the trees of the Northeast and will soon grow to cover the trees of the entire continental United States.
Previews of the app: