They are very poorly drained, organic soils that have a hyperthermic temperature regime and an aquic moisture regime. The more shallow soils are dominant in the southern part, and the deeper soils are dominant near Lake Okeechobee. Especially important in Dade, Monroe, and Collier Counties are soils that are shallow and very shallow to limestone and marl. Sawgrass, pickleweed, willow, buttonbush, and maidencane are the dominant marsh species. Baldcypress is the dominant swamp species.
Mangroves grow in saltwater swamps along the eastern and southern coasts.
Soil Conservation Service Handbook 296.