forming mass stands (see slide 11 in Appendix D) , and 

 competing successfully with Cirsium arvense (Canada thistle) . 

 The plants were heavily browsed in patches, probably by wild 

 game. The subpopulation just above the reservoir was 

 estimated to consist of over 5,000 aerial stems covering about 

 10 acres. Plants were more scattered in this subpopulation, 

 were less heavily browsed, and a more significant number were 

 small and vegetative. On the survey date of August 17 plants 

 at both populations were flowering with some immature fruit 

 developed. There is some question whether or not this species 

 reproduces vegetatively . Welsh et al. (1987) state that it is 

 "lacking, or rarely with rhizomes." The dense stands of the 

 upstream subpopulation suggest clonal reproduction, especially 

 considering the high levels of inflorescence predation and 

 infestation of the habitat by rhizomatous weeds. Excavation 

 of underground plant parts was extremely difficult due to the 

 hard soil and heavy vegetation cover; no connections between 

 stems were documented. 



E. MANAGEMENT CONSIDERATIONS 



One subpopulation is heavily impacted by browsing and weeds, 

 but the species remains competitive at the site. The other 

 subpopulation occurs in more pristine habitat, but recently a 

 wide path has been excavated across the Hyalite Creek 

 floodplain nearby (see slide 12 in Appendix D) . This bare 

 ground may provide a route for weed invasion of the Sidalcea 

 habitat. Although the GNF population seems secure at this 

 point, it is limited to a very small area of unique habitat, 

 close to roads and potential development. Considering the 

 species' limited, and oddly disjunct, distribution in Montana, 

 it should continue to be tracked by the MTHP. Forest Service 

 sensitive status is also appropriate. Further searches for S. 

 oregana should be conducted in the vicinity, concentrating on 

 natural meadows in the valley above Hyalite Reservoir. Steps 

 should be taken to monitor and prevent weed invasion of the 

 lower population site, and weed control measures should 

 carefully target exotic species in nearby areas. 



