Identify which USDA hardiness zone the Florida plant is growing in. The state is split between zones 8, 9, and 10. Use a map such as the one listed in "Resources" to determine the temperate zone. Plants that do not grow in the same zone in which you live can be quickly ruled out.
Examine the plant's features. Write down details about the leaf size and shape, colors, flowers and blooming period. Note the time, location and date you saw the plant.
Take pictures of the plant. Zoom in to get closeups of the plant's features. Using a digital camera is best because the photo can easily be emailed to experts on Florida plants.
Cut off a piece of the plant. Use pruning shears and cut just above a node or bloom. Put the cutting between newspaper and press it with something heavy to dry it.
Narrow the plant identification down to a classification. Florida plants usually fall into one of these categories: palms, grasses, trees, shrubs, flowers, vines and ground covers.
Consult plant books that focus on Florida species. Two examples are "Florida Plants for Wildlife: A Selection Guide to Native Trees and Shrubs" and "Florida Wild Flowers and Roadside Plants". They offer a specific description of all the plants that grow in the Sunshine State. See Resources for a link to Florida plant books. You can also find them in bookstores or libraries.
Speak with experts at the University of Florida IFAS Extension Service. They are a section of the University of Florida and Florida A&M University and handles continuing education. The staff will consult with residents on wildlife and agricultural issues. You can email them a picture to help with the identification process.