V. DISCUSSION 



Origin of the Sweetgrass Hills flora is relictual in some sense, as 

 suggested in persistence of two rare montane species, Claytonia 

 lanceolata var. flava and Ranunculus pedatif idus . They are at their 

 lowest state elevations in the Sweetgrass Hills. All four target 

 species as found in the Sweetgrass Hills are highly disjunct in the 

 region; Halimolobos virgata and Ranunculus cardiophyllus are also 

 found in the even more isolated montane setting of the Cypress Hills 

 ca. 100 miles (140 km) farther east in Canada (Brietung 1954) . 



The montane flora as a whole occupies suitable habitat in conditions 

 which are sometimes appreciably different compared to species' habitat 

 elsewhere in Montana and the range at large. This is particularly 

 true of Ranunculus pedatif idus . which has a completely different 

 topographic and hydrologic settings; low and wet in the Sweetgrass 

 Hills compared to high and dry in the Rocky Mountains, and of 

 Claytonia lanceolata var. flava, which appears to have a broader 

 ecological amplitude in the Sweetgrass Hills than any other area of 

 the state. While Sweetgrass Hills vegetation structure may be 

 limiting for birds, as reflected by relatively low numbers of montane 

 bird species (Thompson 1978) , the montane flora of the area is not as 

 tied to habitat structure as avifauna. The origin of the Sweetgrass 

 Hills flora warrants palynological study before floristic composition 

 and biodiversity can be interpreted in biogeographic research. The 

 montane flora in general is incompletely documented for purposes of 

 comparing its diversity with other outlying settings or segments of 

 the Rocky Mountain chain. 



Extended sensitive species survey on Sweetgrass Hills public lands 

 beyond those of BLM may lead to additional information and provide a 

 more complete sensitive species picture across the landscape. 



Additional surveys may also reveal additional sensitive species, as 

 judging by information that was compiled after the field season. It 

 was determined from reviewing the Breitung Cypress Hills flora (1954) 

 that- there are 13 plant species of interest in the Cypress Hills not 

 presently known from the Sweetgrass Hills. These 13 are tracked as 

 state species of concern in Montana and are recommended for 

 consideration in any future botanical work in the Sweetgrass Hills 

 area, particularly in woodland and wetland habitats. They include: 

 Lycopodiiim obscurum, Lilaea scilloides , Sphenopholis obtusata , Carex 

 eburnea . Scirpus nevadensis , Cypripedium passerinum , Orchis 

 rotundifolia , Salix serissima, Mirabilis hirsuta , Potentilla 

 plattensis . Boisduvalia glabella . Viola renifolia, and Aster 

 ptarmicoides . 



Information obtained through this study supports the case for 

 extending floristic analysis and initiating vegetation analysis as 

 baseline. 



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