entire distribution of the species. A frequency, for example, 

 of 67%-99% (Facultative Wetland) means that 67%-99% of sample 

 plots containing the species randomly selected across the 

 range of the species would be wetland. A question mark (?) 

 following an Indicator denotes a tentative assignment based 

 on the botanical literature and not confirmed by regional 

 review. When two indicators are given, they reflect the range 

 from the lowest to the highest frequency of occurrence in 

 wetlands across the regions in which the species is found. A 

 positive (+) or negative (-) sign was used with the 

 Facultative Indicator categories to more specifically define 

 the regional frequency of occurrence in wetlands . The 

 positive sign indicates a frequency toward the higher end of 

 the category (more frequently found in wetlands), and a 

 negative sign indicates a frequency toward the lower end of 

 the category (less frequently found in wetlands). 



Indicator Categories 



Obligate Wetland (OBL) . Occur almost always (estimated 

 probability >99%) under natural conditions in wetlands. 



Facultative Wetland (FACW) ♦ Usually occur in wetlands 

 (estimated probability 67%-99%), but occasionally found in 

 no nwet lands . 



Facultative (FAC). Equally likely to occur in wetlands or 

 nonwetlands (estimated probability 34%-66%). 



Facultative Upland (FACU) . Usually occur in nonwetlands 

 (estimated probability 67%-99%), but occasionally found in 

 wetlands (estimated probability l%-33%). 



Obligate Upland (UPL) . Occur in wetlands in another region, 

 bat occur almost always (estimated probability >99%) under 

 natural conditions in nonwetlands in the region specified. 

 If a species does not occur in wetlands in any region, it is 

 not on the National List . 



The wetland Indicator categories should not be equated to 

 degrees of wetness. Many obligate wetland species occur in 

 permanently or semipermanently flooded wetlands, but a number 

 of obligates also occur and some are restricted to wetlands 

 which are only temporarily or seasonally flooded. The 

 facultative upland species include a diverse collection of 

 plants which range from weedy species adapted to exist in a 

 number of environmentally stressful or disturbed sites 

 (including wetlands) to species in which a portion of the gene 

 pool (an ecotype) always occurs in wetlands. Both the weedy 

 and ecotype representatives of the facultative upland category 

 occur in seasonally and semipermanently flooded wetlands. 



