Physiognomy and Structure: Stands of this macrogroup are wetland forests with generally closed canopies and the characteristic presence or dominance of several broad-leaved evergreen tree species. In some cases the hydrology is strongly influenced by groundwater seepage, but many examples are ombrotrophic, rain fed wetlands.

Floristics: The vegetation of this macrogroup is dominated by woody plants, primarily trees. An open to closed canopy is usually present and consists of a mixture of acidic-tolerant wetland trees such as Acer rubrum, Liriodendron tulipifera, Magnolia virginiana, Nyssa sylvatica, Nyssa biflora, Persea palustris, and Pinus serotina. Some associations may contain Chamaecyparis thyoides, but this species is not diagnostic of this macrogroup. There is generally a dense shrub layer that is dominated by species shared with pocosins or baygalls, such as Arundinaria tecta (= Arundinaria gigantea ssp. tecta), Clethra alnifolia, Cliftonia monophylla, Cyrilla racemiflora, Ilex glabra, Leucothoe axillaris, Lyonia ligustrina, and Lyonia lucida, but includes some species which occur in other saturated wetlands, such as Morella caroliniensis, Persea palustris, Toxicodendron vernix, and Viburnum nudum. The vine Smilax laurifolia may be abundant. The herb layer, if well-developed at all, generally consists of large wetland ferns, such as Osmunda cinnamomea, Osmunda regalis var. spectabilis, Woodwardia virginica, and Woodwardia areolata, with Carex spp. There is some variation according to latitude, with southerly examples generally consisting of broad-leaved evergreen forests, while more northerly examples support more mixed evergreen-deciduous forests. In addition, broad-leaved evergreen species are especially pronounced in the shrub layer of southern examples.

Dynamics:  The evergreen seepage-influenced vegetation types included here are quite heterogeneous in composition and in the role of fire, as well as extensive in geographic range. The streamhead seepages of the sandhills of the Carolinas, Georgia, Florida, and southern Virginia are distinctive in being strongly fire-dominated, having Pinus spp. as a major canopy dominant, and having many shrubs typical of pocosins. A second set of associations ranging from South Carolina through the Gulf Coastal Plain has vegetation that suggests less influence by fire, including hardwood canopies and shrub layers of broad-leaved evergreen shrubs of saturated habitats. A third set, from a wider variety of topographic settings throughout the region, has hardwood canopies and shrub and herb layers with less peatland affinities, more closely related to floodplain communities. Their flora suggests a minor role for fire. Fire is important, but the fire regime appears to be somewhat variable or unclear, because some of the characteristic trees are fire-intolerant (e.g., Magnolia), while others are fire-dependent (Pinus serotina). Fire frequency is lengthened by the wetness of the soil. This vegetation occurs in landscapes that had frequent fire under natural conditions, but the wetness sometimes limited fire spread, creating a less frequent fire-return interval. Natural fire intensity varies among alliances and associations, with some readily producing intense fire when they burn, while others probably experiencing only low-intensity fires because of low flammability. Persea palustris is suffering the effects of a beetle-borne fungus which is killing these trees in stands of this vegetation as well as upland maritime forests. This fungus (Ophiostoma sp.) is carried by the redbay ambrosia beetle (Xyleborus glabratus), introduced from Asia.