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Coastal Plain / Outer Piedmont Acidic Seepage Swamp (CEGL006238)

This wet forest type is non-alluvial, so fed by groundwater rather than alluvial floodplain systems fed by flowing water and flooding from nearby streams. Topography is generally those of toe-slopes (transitioning from other plant communities) and bottomlands where soils are more or less permanently saturated. On slopes, you can sometimes see groundwater discharge from seepages trickling through the ground. Expect to see dominant Red Maple and Black Gum canopy (though both are common throughout other plant communities too).  Specialist understory trees and shrubs like Magnolia virginiana and Viburnum nudum can be useful indicators. Herbaceous layers can be more dense than surrounding forest communities (especially in rugged Fall Zone soils), with sedges and ferns being typical. 

This plant community is badly threatened locally by development and changes to hydrology from increased impervious surface and other human interference. In the garden context, it’s unlikely that you will have remnant examples of this plant community. But, plants from this list are good options for creating ersatz seepage swamps in wet swales or slow-draining raingardens where persistently wet soils may provide a reasonable analogue for the natural hydrology.


For more help with plant selection, you can return to our Compendium here.

Indicator Species: Acer rubrum, Nyssa sylvatica, Osmundastrum cinnamomeum, Viburnum nudum, Magnolia virginiana, Woodwardia areolate

High constancy and high cover.

These species are both common in this community and because of their size and spread or frequency with which they pop up, they make up the bulk of the plants on site.

Acer rubrum                                        Nyssa sylvatica

Ilex opaca                                           Quercus alba

Lindera benzoin                                  Rhododendron periclymenoides

Liriodendron tulipifera                         Viburnum nudum

Magnolia virginiana

High constancy, but low cover.

These species occur frequently but may only pop up here and there across the site. Another good set of species to get on site once you’ve covered the fundamental components above, but don’t go overboard.

Arisaema triphyllum                            Chionanthus virginicus

Dioscorea villosa                                Euonymus americanus

Carex intumescens                             Ilex verticillata

Cinna arundinacea                              Viburnum dentatum

Juncus effusus                                    Parthenocissus quinquefolia

Leersia virginica


Low constancy, but high cover.

These species pop up less frequently but when they do, they tend to be relatively major components of the landscape either because of their size (in the case of trees and large shrubs), because they form large stands, or because they do well exploiting a certain niche on site.


Carpinus caroliniana

Low constancy and low cover.

These species are less common and tend to form smaller stands or be fewer individuals scattered around a site.

Apios americana                        Symphyotrichum lateriflorum               Alnus serrulata

Chelone glabra                          Thalictrum pubescens                          Aronia arbutifolia

Eutrochium fistulosum               Carex crinita                                        Cornus florida

Lobelia cardinalis                       Carex folliculata                                  Fraxinus pennsylvanica

Maianthemum racemosum        Carex lurida                                         Prunus serotina

Saururus cernuus                      Chasmanthium laxum                          Quercus phellos

Solidago rugosa                        Dichanthelium clandestinum                Quercus rubra

                                                                                                               Sambucus canadensis

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