site names; these correspond to the occurrence 

 numbers provided in the tables and computer print- 

 outs. 



3. HISTORICAL SITES (MONTANA): None. 



4. UNVERIFIED/UNDOCUMENTED REPORTS (MONTANA): None. 



5. AREAS SURVEYED BUT SPECIES NOT LOCATED: Field 

 surveys on the Lewis & Clark National Forest in 

 1988 emphasized thorough searches along 

 tributaries of the Sun River in the Front Range. 

 Drainages which were surveyed on foot, but in 

 which no sites for O. rotundifolia were found, 

 include: 



a. Cutreef Creek (T21N, R9W, Sections 26, 27, 

 35, 36). 



b. Patricks Basin (downstream along Lange Creek 

 from Stovepipe Creek; T21N, RlOW, Sections 

 11, 13, 14). 



c. Stovepipe Creek (T21N, RlOW, Sections 13, 24; 

 T21N, R9W, Section 18). 



No additional suitable habitat, aside from the 

 White River and Butcher Mountain Meadow sites, was 

 observed in the South Fork Flathead River 

 drainage. Moist forests and meadow areas were 

 searched in the vicinity of Big Prairie (lower 

 Cayuse Creek) , but no populations were found. 



E . HABITAT 



ASSOCIATED VEGETATION: In Montana, Orchis 

 rotundifolia is found in mossy, moist seepage 

 areas, along stream shores, and on the ecotonal 

 margins of sphagnum bogs, often in full or partial 

 shade of coniferous trees. The sites are most 

 typically associated with forests of Picea 

 engelmannii (Engelmann Spruce) ; in some areas it 

 also occurs with Pinus contorta (Lodgepole Pine) . 

 Additional frequently associated plants, which 

 include a large number of other orchid species, 

 include: 



Angelica arguta (Sharptooth Angelica) 



Carex aurea (Golden Sedge) 



Carex dioica (= C. gynocrates ; Yellow-bog Sedge) 



Carex disperma (Softleaved Sedge) 



Carex interior (Inland Sedge) 



Corallorhiza trif ida (Yellow Coral-root) 



Cornus canadensis (Bunchberry) 



