Peter Belhumeur just wanted to know what type of tree was outside his apartment. He scanned field guides, looking for willowlike leaves with a wavy, spiked edge, but he couldn’t find the right one.

WASHINGTON — If you've ever wondered what type of tree was nearby but didn't have a guide book, a new smartphone app allows users with no formal training to satisfy their curiosity and contribute to ...

Identifying trees can be as simple as digging your phone out of your pocket. The Arbor Day Foundation has developed an application to make identifying trees even easy for iPhone and iPod Touch users.