unofficial. The status of each species was determined by reference to 

 verified herbarium records, accounts in published and unpublished literature, 

 and communications with herbaria and individuals knowledgeable about the flora 

 of Montana. The figures in parentheses indicate the total number of plant 

 taxa included in each category. 



EKDANGERED (7). Any species, subspecies or variety in danger of 

 extirpation throughout all or a significant portion of its range in 

 Montana. Specific threats to known populations of these plants have 

 been identified. 



THREATENED (25). Any species, subspecies or variety likely to become 

 endangered throughout all or a significant portion of its range in 

 Montana in the foreseeable future. Specific threats to known 

 populations of these plants have been identified. 



SENSITIVE (260). Any species, subspecies or variety that is known from 

 a limited number of populations in Montana, or that occurs principally 

 in restricted habitats considered vulnerable to man-caused disturbances. 

 These species may have a restricted range in Montana, or they may be 

 sparsely distributed over a larger area. Plants designated as sensitive 

 may possibly become threatened or endangered in the state if impacts to 

 known populations occur. 



POSSIBLY EXTIRPATED (2). Recent field searches indicate that these 

 species, once known to occur in Montana, may no longer occur in the 

 state. 



WATCH LIST (37). These species, subspecies or varieties are considered 

 too common to be listed as sensitive, but more information is needed for 

 certainty. In addition, the degree of threat is difficult to detrmine 

 for many of these taxa. Populations should be inventoried and 

 periodically monitored in order to gain additional information. 

 Occurrences of these plants are being tracked by the Montana Natural 

 Heritage Program. 



LIMITED DISTRIBUTION (44). These species, subspecies or varieties are 

 limited to a small area of Montana (usually two counties or less), but 

 are considered too abundant within that area to be sensitive. These 

 taxa are included here because of their phytogeographic significance, 

 but, except for state endemics, their populations are not currently 

 being tracked by the Montana Natural Heritage Program. 



UNDETERMINED (71). Taxa for which there is some question as to identity 

 or taxonomic status are included in this category. Also included are 

 species reported to be in Montana, but for which we have no verifiable 

 evidence of their presence here. 



REJECTED (670). Species, subspecies and varieties determined not to be 

 endangered, threatened, sensitive, potentially sensitive (watch list), 

 or of limited distribution were rejected. This category includes taxa 

 previously rejected by the Montana Rare Plant Project (Lesica et al. 

 1984), as well as those that have been rejected since that time. 



NATURAL HERITAGE PROGRAM STATUS 



The Nature Conservancy has devised a standarized ranking system that is used 

 by most Natural Heritage Programs. Plant species, subspecies and varieties 

 are ranked on the basis of their global (range-wide) rarity, and their rarity 

 within each state, using the following categories: 



