10 



Pvrola uniflora (Woodnymph) 

 Salix scouleriana (Scouler Willow) 

 Smilacina stellata (Starry Solomon-plume) 

 Streptopus amplexifolius (Clasping-leaved Twisted- 

 stalk) 

 Symphoricarpos albus (Common Snowberry) 

 Thalictrum occidentale (Western Meadowrue) 



The co-occurrence of Orchis rotundifolia with C. 

 passerinum at many sites, owing to similar 

 ecological requirements, should be emphasized. 

 Both species are U.S. Forest Service Region 1 

 sensitive species, and careful management will be 

 needed to protect the following sites where the 

 two species occur together: 



Blacktail Gulch (006) 



Butcher Mountain Meadows (003) 



Clary Coulee (010) 



Dry Fork Lange Creek (007) 



Green Timber Basin (002) 



North Fork Birch Creek (Oil) 



White River (004) 



2. TOPOGRAPHY: In Montana, populations of C. 

 passerinum are most often found on gently sloping 

 areas, varying from approximately 0-10% slope. It 

 was found on all aspects. 



The known sites in Montana range from 1280 m. (4200 

 ft.) to 1740 m. (5700 ft.) in elevation. 



3. SOIL RELATIONSHIPS: All of the known sites for C. 

 passerinum in Montana occur in areas with calcareous 

 substrates. The soils are typically weathered from 

 beds of the Madison Limestone formation, especially 

 in the Rocky Mountain Front Range (Veseth and 

 Montagne 1980) . The most important feature of all 

 known sites appears to be semi-permanent water 

 seepage near the surface. Cvpripedium passerinum is 

 often found on moist, mossy hummocks in these 

 seepage zones. 



4. REGIONAL CLIMATE: The climate of northwestern 

 Montana west of the Continental Divide can generally 

 be classified as moist and temperate, while the 

 Front Range is more likely to be influenced by cold, 

 dry continental air masses. For the distributional 

 area of C. passerinum in Montana, the nearest 

 climatological stations are located at Gibson Dam 



(1399 m. (4590 ft.)) and Hungry Horse Dam (963 m. 



(3160 ft.)). Data for the period 1951-1980 are 

 provided by the U.S. Department of Commerce (1982). 

 At Gibson Dam, the mean annual precipitation was 



