Gymnosperms are woody plants that produce seeds, but, unlike the flowering plants (angiosperms), the seeds are not enclosed inside an ovary. This means that instead of developing inside a fruit, such as a berry or acorn, gymnosperm seeds are more exposed. Often they are housed in somewhat open structures called cones. (The seeds, or the structures that contain them, sometimes appear quite similar to fruits, though, as is the case with ginkgo and juniper trees.)

In the southeastern United States almost all the native gymnosperms are trees, while the few that are not are shrubs. Most of them have leaves in the form of needles or scales, and are evergreen. Pine trees (Pinus) are among the most common and widespread gymnosperms in the region. Others include firs (Abies), hemlocks (Tsuga), junipers or cedars (Juniperus), and bald-cypresses (Taxodium).

The word gymnosperm comes from Greek, and literally means "naked seed" (gymnos = naked, sperma = seed).