Physiognomy and Structure: No Data Available

Floristics: Canopy closure ranges from closed to quite open. Plot data from 38 Virginia and Maryland stands indicate that Acer rubrum and Nyssa sylvatica are consistently dominant overstory species. Liriodendron tulipifera is a frequent but minor overstory associate, and Pinus taeda or Liquidambar styraciflua is occasional in the canopy. Magnolia virginiana is a frequent overstory associate and usually dominant in a subcanopy layer or codominant with Ilex opaca. Trees tend to be slow-growing and of less than optimal stature in the wet, unstable habitats. Shrub layers tend to be dense and diverse, characteristically containing Viburnum nudum var. nudum, Vaccinium corymbosum, Smilax rotundifolia, Ilex verticillata, and Lindera benzoin. In parts of the range, Clethra alnifolia is a dominant shrub, while in New Jersey, Chamaedaphne calyculata and Gaylussacia frondosa are present. Additional, less constant shrub associates are Rhododendron viscosum, Eubotrys racemosa (= Leucothoe racemosa), Chionanthus virginicus, Viburnum dentatum, Toxicodendron vernix, and Carpinus caroliniana. The herb layer varies from dense to sparse. Osmunda cinnamomea and Woodwardia areolata are generally the most constant and abundant herbs, but Symplocarpus foetidus is a patch-dominant in approximately two-thirds of the Virginia and Maryland stands. Additional characteristic herbs occurring at low cover include Arisaema triphyllum ssp. pusillum, Carex atlantica, Carex debilis var. debilis, Carex folliculata, Carex intumescens, Carex lonchocarpa, Carex seorsa, Carex styloflexa, Chelone glabra, Impatiens capensis, Lycopus virginicus, Mitchella repens, Osmunda regalis var. spectabilis, Platanthera clavellata, Viola cucullata, and Viola x primulifolia. Regionally uncommon or rare species that may be locally abundant in this type include Helonias bullata, Parnassia asarifolia, Carex collinsii, and Bartonia paniculata.

Dynamics:  Trees tend to be slow-growing and of less than optimal stature in the wet, unstable habitats. Additionally, these swamps tend to border dry, sandy uplands supporting fire-prone oak/heath forests. Occasional fires, burning into the swamps from the uplands during dry periods, may have once influenced the composition and physiognomy of this type. However, fire has now been excluded from almost all areas within the range. An exception is at Fort A.P. Hill Military Reservation, where military training results in frequent incendiary fires in a roughly 5000-ha area. Stands of this community are very susceptible to flooding from beaver activities, which usually results in the destruction or extreme alteration of a stand. In New Jersey, this community is often situated adjacent to Chamaecyparis thyoides-dominated swamp and may replace it after logging.