USDA Plant Status Categories
Courtesy of the USDA
National Indicators reflect the range ofestimated probabilities (expressed as a frequency of occurrence)of a species occurring in wetlands versus non-wetland acrossthe entire distribution of the species. A frequency, for example,of 67%-99% (Facultative Wetland) means that 67%-99% of sampleplots containing the species randomly selected across the rangeof the species would be wetland. When two indicators are given,they reflect the range from the lowest to the highest frequencyof occurrence in wetlands across the regions in which the speciesis found. A positive (+) or negative (-) sign was used withthe Facultative Indicator categories to more specifically definethe regional frequency of occurrence in wetlands. The positivesign indicates a frequency toward the higher end of the category(more frequently found in wetlands), and a negative sign indicatesa frequency toward the lower end of the category (less frequentlyfound in wetlands). A question mark (?) following a NationalIndicator denotes a tentative assignment based on the botanicalliterature and not confirmed by regional review.
Regional Indicators express the estimatedprobability (likelihood) of a species occurring in wetlandsversus non-wetlands in the region. Regional Indicators reflectthe unanimous agreement of the Regional Interagency ReviewPanel. An asterisk (*) following a regional Indicator identifiestentative assignments based on limited information from whichto determine the indicator status.
The wetland indicator categories should not be equated todegrees of wetness. Many obligate wetland species occur inpermanently or semi-permanently flooded wetlands, but a numberof obligates also occur in and some are restricted to wetlandswhich are only temporarily or seasonally flooded. The facultativeupland species include a diverse collection of plants, whichrange from weedy species adapted to exist in a number of environmentallystressful or disturbed sites (including wetlands), to speciesin which a portion of the gene pool (an ecotype) always occursin wetlands. Both the weedy and ecotype representatives ofthe facultative upland category occur in seasonally and semi-permanentlyflooded wetlands.