Wet flatwoods are pine forests with a sparse or absent midstory and a dense groundcover of hydrophytic grasses, herbs, and low shrubs. The pine canopy typically consists of one or a combination of longleaf pine (Pinus palustris), slash pine (P. elliottii), pond pine (P. serotina), or South Florida slash pine (P. elliottii var. densa). The subcanopy, if present, consists of scattered sweetbay (Magnolia virginiana), swamp bay (Persea palustris), loblolly bay (Gordonia lasianthus), pond cypress (Taxodium ascendens), dahoon (Ilex cassine), titi (Cyrilla racemiflora), and/or wax myrtle (Myrica cerifera). Shrubs include large gallberry (Ilex coriacea), fetterbush (Lyonia lucida), titi, black titi (Cliftonia monophylla), sweet pepperbush (Clethra alnifolia), red chokeberry (Photinia pyrifolia), and azaleas (Rhododendron canescens, R. viscosum).
Mesic flatwoods is the most widespread natural community in Florida, covering the flat sandy terraces left behind by former high stands of sea level during the Plio-Pleistocene. Mesic flatwoods is characterized by an open canopy of tall pines and a dense, low ground layer of low shrubs, grasses, and forbs. Longleaf pine (Pinus palustris) is the principal canopy tree in northern and Central Florida, and South Florida slash pine (P. elliottii var. densa) forms the canopy south of Lake Okeechobee. Characteristic shrubs include saw palmetto (Serenoa repens), gallberry (Ilex glabra), coastalplain staggerbush (Lyonia fruticosa), and fetterbush (Lyonia lucida). Rhizomatous dwarf shrubs, usually less than two feet tall, are common and include dwarf live oak (Quercus minima), runner oak (Q. elliottii), shiny blueberry (Vaccinium myrsinites), Darrow’s blueberry (V. darrowii), and dwarf huckleberry (Gaylussacia dumosa).
Scrubby flatwoods occur on slight rises within mesic flatwoods and in transitional areas between scrub and mesic flatwoods. Soils of scrubby flatwoods are moderately well-drained sands with or without a spodic horizon. Scrubby flatwoods have an open canopy of widely spaced pine trees and a low, shrubby understory dominated by scrub oaks and saw palmetto, often interspersed with areas of barren white sand. Principal canopy species are longleaf pine (Pinus palustris) and slash pine (P. elliottii) in northern and Central Florida, and South Florida slash pine (P. elliottii var. densa) south of Lake Okeechobee. The shrub layer consists of one or more of the four scrub oaks, sand live oak (Quercus geminata), myrtle oak (Q. myrtifolia), Chapman’s oak (Q. chapmanii), and scrub oak (Q. inopina), and typical shrubs of mesic flatwoods including saw palmetto (Serenoa repens), gallberry (Ilex glabra), rusty staggerbush (Lyonia ferruginea), fetterbush (L. lucida), coastalplain staggerbush (L. fruticosa), and deerberry (Vaccinium stamineum).
Pine rockland occurs on relatively flat, moderately to well drained terrain from two to seven meters above sea level. The oolitic limestone is at or very near the surface, and there is very little soil development. Soils are generally composed of small accumulations of nutrient-poor sand, marl, clayey loam, and organic debris in depressions and crevices in the rock surface. Pine rockland has an open canopy of South Florida slash pine, generally with multiple age classes. The diverse, open shrub/subcanopy layer is composed of more than 100 species of palms and hardwoods, including saw palmetto (Serenoa repens), cabbage palm (Sabal palmetto), silver palm (Coccothrinax argentata), brittle thatch palm (Thrinax morrisii), wax myrtle (Myrica cerifera), myrsine (Rapanea punctata), poisonwood (Metopium toxiferum), locustberry (Byrsonima lucida), varnishleaf (Dodonaea viscosa), tetrazygia (Tetrazygia bicolor), rough velvetseed (Guettarda scabra), marlberry (Ardisia escallonioides), mangrove berry (Psidium longipes), willow bustic (Sideroxylon salicifolium), winged sumac (Rhus copallinum). Short-statured shrubs include running oak (Quercus elliottii), white indigoberry (Randia aculeata), Christmas berry (Crossopetalum ilicifolium), redgal (Morinda royoc), and snowberry (Chiococca alba).
Source: Guide to the Natural Communities of Florida, 2010 Edition