The hottest gardening smart-phone application of 2011 is one that's making Marylanders proud. It's Leafsnap, a tree-identification and databank app, and it's the work of the University of Maryland, in collaboration with the Smithsonian Institution and Columbia University (and funded by the National Science Foundation). So far, its database of trees covers all the trees native to the Northeastern U.S. (including Maryland), but soon it'll cover all of continental U.S. It works for iPhones and Androids, too.
How it Works
Here's how it works. Just hold a leaf against a white surface and photograph it, and Leafsnap will identify it for you. Some reviewers have complained that they don't always have a white piece of paper handy with them in the wild but really, how much space does one piece of paper take up?
Leafsnap identifies trees through the use of mathematical techniques developed for face recognition, applied to tree species. But it's complicated because within a single species, leaves can have quite diverse shapes, and leaves from different species are sometimes quite similar. So there were huge technical challenges, but the resulting program actually works!
In addition to identifying trees, the app contains a visual dictionary of leaf types that can be matched to names and descriptions, plus photos and information about the tree's flowers, fruit, seeds and bark. It collects all of your identified trees in one place, and adds them to their public database, which helps others in their use of Leafsnap and helps science, too. Oh, and there's even a cool leaf guessing game!
Here's a quick video from the Smithsonian explaining how Leafsnap works.