Vegetation Classification and Mapping Project Report - USGS

USGS-NPS Vegetation Mapping Program
Colonial National Historical Park
Colonial National Historical Park Inventory Notes: Information not available.
GLOBAL INFORMATION
USNVC CLASSIFICATION
Physiognomic Class Herbaceous Vegetation (V)
Physiognomic Subclass Perennial forb vegetation (V.B.)
Physiognomic Group Temperate or subpolar perennial forb vegetation (V.B.2.)
Physiognomic Subgroup Natural/Semi-natural temperate or subpolar perennial forb vegetation (V.B.2.N.)
Formation Tidal temperate perennial forb vegetation (V.B.2.N.g.)
Alliance Peltandra virginica - Pontederia cordata Tidal Herbaceous Alliance (A.1703)
Alliance (English name) Green Arrow-arum - Pickerelweed Tidal Herbaceous Alliance
Association Hibiscus moscheutos - Polygonum punctatum - Peltandra virginica Tidal
Herbaceous Vegetation
Association (English name) Eastern Rosemallow - Dotted Smartweed - Green Arrow-arum Tidal
Herbaceous Vegetation
Ecological System(s): Northern Atlantic Coastal Plain Fresh and Oligohaline Tidal Marsh
(CES203.516).
GLOBAL DESCRIPTION
Concept Summary: This association is a diverse oligohaline marsh characterized by variable
dominance of species found in the Chesapeake and Delaware bays. Species that form locally
dominant patches can include Polygonum arifolium (halberdleaf tearthumb), Hibiscus
moscheutos ssp. moscheutos (crimsoneyed rosemallow), Polygonum punctatum (dotted
smartweed), Peltandra virginica (green arrow arum), Leersia oryzoides (rice cutgrass),
Polygonum sagittatum (arrowleaf tearthumb), Mikania scandens (climbing hempvine), Spartina
cynosuroides (big cordgrass), and Toxicodendron radicans (eastern poison ivy), among others.
All of these species are able to tolerate a broad range of halinity, and the high mean species
richness of this type suggests that it is generally restricted to only slightly oligohaline habitats.
Typha angustifolia (narrowleaf cattail) and Spartina cynosuroides (big cordgrass) often form
large dominance patches. Infrequently present are several species that are more specific to
oligohaline conditions, including Echinochloa walteri (coast cockspur grass), Kosteletzkya
virginica (Virginia saltmarsh mallow), Pluchea odorata (sweetscent), Rumex verticillatus
(swamp dock), Sagittaria lancifolia (bulltongue arrowhead), and Teucrium canadense (Canada
germander). The colonial sedge Carex stricta sometimes forms local dominance patches,
characteristically on hummocks raised 20-25 cm above the primary marsh surface.
Environmental Description: Most stands are located near the edge of an extensive marsh but
set by the main river channel and often bordered by scattered clumps of shrubs. There is often
hummock-and-hollow microtopography.
Vegetation Description: These are diverse oligohaline marshes characterized by variable
dominance patterns but generally containing Polygonum arifolium (halberdleaf tearthumb),
Hibiscus moscheutos ssp. moscheutos (crimsoneyed rosemallow), Polygonum punctatum (dotted
smartweed), Peltandra virginica (green arrow arum), Leersia oryzoides (rice cutgrass),
Polygonum sagittatum (arrowleaf tearthumb), Mikania scandens (climbing hempvine), and
Toxicodendron radicans (eastern poison ivy). Bidens laevis (smooth beggartick), Cicuta
maculata (spotted water hemlock), Cuscuta sp. (a dodder), Impatiens capensis (jewelweed),
Lycopus americanus (American water horehound), and Sagittaria latifolia (broadleaf
arrowhead), and graminoids such as Typha latifolia (broadleaf cattail) and Schoenoplectus
fluviatilis (river bulrush) may also be present at variable cover. Typha angustifolia (narrowleaf
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