National Capital Parks-East - Wetlands, Marshes and Swamps

The streams that transect the parks of National Capital Parks-East (NACE) usually end in tidal swamps and marshes that are frequently encountered below an elevation of three meters (9.8 feet). Kenilworth Park contains approximately 24 hectares (60 acres) of reconstructed tidal emergent marsh along the Anacostia River. These are the last large tidal wetlands remaining in the District of Columbia. A large Spatterdock Lily (Nuphar advena) marsh dominates the cove on the east side of Mockley Point in Piscataway Park. Other large tidal marshes are found at the mouth of Accokeek Creek and at Calamus Marsh just south of Bull Cove, also in Piscataway Park. These marshes extend inland at least 300 meters (327 yards) from the Potomac River shore. Both marshes are dominated by Sweetflag (Acorus calamus), but Narrow-leaved Cattail (Typha angustifolia), Rice Cut Grass (Leersia oryzoides), Jewelweed (Impatiens capensis), Halberd-leaved Tearthumb (Polygonum arifolium) and River Bullrush (Schoenoplectus fluviatilis) are also common. A total of 104 vascular plant taxa have been found to be associated with these marshes.

Extensive fringe swamps often surround the marshes on their inland sides. A prime example is the large swamp complex that occurs just southeast of Mockley Point. Species that typify these swamps include Appalachian Arrow-head (Sagittaria australis), Gray"s Sedge (Carex grayi), Heart-leaved Groundsel (Senecio aureus), Blue Marsh Violet (Viola cuculata), Common Woodreed (Cinna arundinacea), Yellow-green Sedge (Carex lurida), Golden Club (Orontium aquaticum), Winterberry (Ilex verticillata), Smooth Alder (Alnus serrulata), Arrow-wood Viburnum (Viburnum dentatum), Virginia Willow (Itea virginica), Sweetbay Magnolia (Magnolia virginiana), Red Ash (Fraxinus pennsylvanica) and Button Bush (Cephalanthus occidentalis). The White Turtlehead (Chelone glabra) and the Maryland state endangered Swamp Lousewort (Pedicularis lanceolata), two plants from the family Scrophulariaceae, can be found in the Mockley Point Swamp, and each serve as the host plant of the state rare Baltimore Checkerspot Butterfly. A total of 150 vascular plant taxa have been observed to be associated with these swamps as well as many species of reptiles and amphibians such as Spotted Turtles (Clemmys guttata) and Spotted and Marbled Salamanders (Ambystoma maculatum and Ambystoma opacum).

Other significant wetlands in NACE include the Northern (McAteean) Magnolia Bog and a smaller gravel bog at Oxon Run Parkway. This site contains the only populations in NACE of Bog Fern (Thelypteris simulata), Poison Sumac (Toxicodendron vernix), Male-berry (Lyonia ligustrina), Southern Clubmoss (Lycopodiella appressa), and Southern Twayblade Orchid (Listera australis).