Wetlands are areas that contain hydrophytic plants as the predominant vegetation. Hydrophytic vegetation are plants that have physiological or morphological adaptations to exist in the soils that are void of oxygen for a period of one week or more during their growing season. This is usually the result of periodic or permanent saturation of the soil, either by groundwater, surface water or adjacent bodies of water.
The United States Fish and Wildlife Service (USFWS), in cooperation with the United States Army Corps of Engineers (USACE), Environmental Protections Agency (EPA) and the Soil Conservation Service, has developed a classification system that assigns a "wetland indicator status" to most plant species. The indicator status is represented by a category that defines the estimated probability of a species occurring in wetlands. The status of plants can be found in the USFWS Biological Report 88 (26.1), National List of Plant Species That Occur in Wetlands: Northeast (Region 1). The indicator status categories are as follows:
OBLIGATE WETLAND OBL Plants that occur almost always (estimated probability >99%) in wetlands under natural conditions.
FACULTATIVE WETLAND FACW Plants that occur usually (estimated probability 67% to 99%) in wetlands, but also occur (estimated probability 1% to 33%) in non-wetlands.
FACULTATIVE FAC Plants with a similar likelihood (estimated probability 33% to 67%) of occurring in both wetlands and non-wetlands.
FACULTATIVE UPLAND FACU Plants that occur sometimes (estimated probability 1% to 33%) in wetlands, but occur more often (estimated probability >67% to 99%) in non-wetlands.
OBLIGATE UPLAND UPL Plants that occur rarely (estimated probability of <1%) in wetlands, but occur almost always (estimated probability >99%) in non-wetlands under natural conditions.
NO INDICATOR NI Plant species for which insufficient information was available to determine an indicator status.
* (Corps of Engineers Wetlands Delineation Manual, Department of the Army, by Environmental Laboratory, January 1987.)
Swamp dog-hobble (Leucothoe racemosa) - This species is listed as a species of special concern in the state of Pennsylvania. Pike Co., June 200
Pickerelweed (Pontederia cordata) - Pike Co., July 2006
Sedges (Carex spp.)
Poison Sumac (Toxicodendron vernix) - Chester Co.
Wild rice (Zizania aquatica) is listed as under the Pennsylvania Wild Plant Conservation Act - Delaware Co.
The wild rice in the foreground of this photo was avoided by the construction work - Delaware Co.
River bulrush (Schoenoplectus fluviatilis) is designated as a rare species in Pennsylvania - Northumberland Co., July 2000
New York Ironweed (Vernonia noveboracensis) is a common wetland plant.