Leafsnap was developed by researchers from Columbia University, the University of Maryland and the Smithsonian Institution. It uses visual recognition software to identify tree species from the appearance of their leaves. The app currently includes trees found in the northeastern United States and Canada.
» RELATED: Indoor gardening: 21 easy-to-care-for plants
Plantifier is a community-based app that allows users to upload a photo of an unknown plant. The image-recognition tool tasks users of MyGarden.org with trying to recognize the pictured plant as quickly as possible.
iNaturalist is similar to Plantifier in that it relies on the community to identify the plants photographed and uploaded. Users can also discuss their findings. It's a joint initiative of the California Academy of Sciences and the National Geographic Society.
» RELATED: How to participate in the rise of gardening using what you have
iPflanzen claims to "accurately identify plants from the garden, park, forest or home." It contains about 1,500 plants in its database and requires users to enter information about the plant — including the leaf shape or fruit color — to identify it.
Pl@ntNet allows users to identify species of plants from pictures. Uploaded images are automatically compared to thousands of photos in the app's botanical databases. Users are encouraged to upload a good image by zooming in on their plant and tapping to focus the camera.