Free iPhone App identifies Tree Leaves

A new iPhone app called LeafSnap is a field guide for tech-friendly naturalists. It can identify a tree’s species by analyzing a photograph of its leaf.

Point your smartphone’s camera at one of nature’s solar cells (laid out flat on a white piece of paper) and the app will go to work. It separates the leaf from the background, and then analyzes the leaf’s shape.

The algorithm, designed by facial recognition experts at Columbia University and the University of Maryland, gets measurements from numerous points along the leaf’s outline. These are then compared to an encyclopedic database of leaves — kindly donated by the Smithsonian Institution and non-profit nature-photography group Finding Species — to give you a result.