From the USDA Blog:
Recently the PLANTS website crossed a milestone with the uploading of its 50,000th image.
The database, managed by the National Plant Data Team at the USDA Natural Resources Conservation Service’s East National Technology Support Center, hosts images of plants that grow in the U.S. and its territories.
Besides images, PLANTS provides basic information on plants, including scientific names and distribution. It is used worldwide by scientists, educators, conservationists, students, farmers, horticulturists and others. All of this information assists people in identifying plants with the correct scientific names.
The photos in the database have come from various sources, with many submitted by members of the public.
Direct to PLANTS Image Search Database
Direct to PLANTS Homepage and Reference Info