10 



Cornus stolonifera (Red Osier Dogwood) 

 Cypripedium passerinum (Sparrow' s-egg Lady's- 



slipper) 

 Disporum trachvcarpum (Wartberry Fairy-bell) 

 Equisetum arvense (Field Horsetail) 

 E quisetum scirpoides (Sedgelike Horsetail) 

 Galium boreale (Northern Bedstraw) 

 Habenaria dilatata (White Bog-orchid) 

 Habenaria h yperborea (Northern Green Bog-orchid) 

 Habenaria obtusata (Blunt-leaf Rein-orchid) 

 Ledum qlandulosum (Trapper's Tea) 

 Linnaea borealis (Western Twinflower) 

 Listera borealis (Northern Twayblade) 

 Listera convallarioides (Broad-lipped Twayblade) 

 Mitella nuda (Bare-stemmed Mitrewort) 

 Osmorhiza chilensis (Mountain Sweet-root) 

 Pyrola 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 C ypripedium passerinum with 

 O. rotundifolia at many sites, owing to the 

 similar ecological requirements of both species, 

 should be emphasized. Both plants are U.S. Forest 

 Service Region 1 sensitive species, and careful 

 management will be needed to protect the following 

 sites where they 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 O. 

 rotundifolia 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 1390 m. 

 (4560 ft.) to 1805 m. (5920 ft.). 



3. SOIL RELATIONSHIPS: All of the known sites for 0. 

 rotundifolia 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) . One of the most 



