The associated vegetation is sparse, whether it is a locaHzed dry microhabitat or prevailing in a 

 harsh landscape. It is dominated or co-dominated in the study area by Stipa comata as it is in 

 Pondera County. In Beaverhead County it has been documented in grassland and steppe 

 dominated by Agropyron spicatum, with or without Artemisia tridentata var. wyomingensis, and 

 less often with Artemisia arbuscida. The following representative list of associated species in 

 Montana reflects major differences between the three counties where it has been recently 

 documented. The asterisked species are found at the Ruby Range site, the species marked by "+" 

 are found at the Beaverhead County sites, and the species marked by "^" are found at the disjunct 

 Teton County site. Most species on this list are associated with Oryzopsis contracta in only one 

 of the three counties, further evidence that this species has broad ecological amplitude. 



Agropyron smithii^ 



Agropyron spicatum *+ 



Allium textile* 



Arenaria kingii+ 



Artemisia arbuscula+ 



Artemisia frigida+ 



Artemisia tridentata var. wyomingensis+ 



Aster scopulorum *+ 



Astragalus gilviflorus'^ 



Astragalus pectinatus^ 



Astragalus vexilliflexus* 



Atriplex gairdneri*^ 



Bouteloua gracilis^ 



Br am us tectorum+ 



Carex fdifolia^ 



Chrysothamnus nauseosus* 



Commandra umbel lata * 



Cordylanthus ramosus+ 



Erigergon cespitosus^ 



Erigeron ochroleucus var. scribneri* 



Eriogonum flavum^ 



Galium boreale^ 



Gutierrezia sarothrae *+ 



Hymenopappus richardsonii^ 



Koeleria macranthera * 



Lesquerella alpina*+ 



Linum austral e^ 



Linum lewisii* 



Melilotus officinalis'^ 



Oejwthera cespitosa'^ 



Oryzopsis hymenoides+ 



Parornychia sessiliflora^ 



Phacelia linearis+ 



Phlox hoodii* 



Phlox longifolia+ 



Poa secunda*+ 



Stipa comata+ 



38 



