from Schassberger 1990). It is believed that seeds fall, remaining near 

 the parent plant, and are aided by gravity on steep slopes, since the 

 seeds have no appendages to aid in long-distance dispersal. 



4. BIOLOGICAL INTERACTIONS 



a. COMPETITION: Species in the genus Astragalus rarely tolerate 

 direct competition or shade cast by other plants (Barneby 1964). Most 

 populations are on barren ground. Total foliage cover rarely 

 approached or exceeded 50%. Sites with large non-flowering plants 

 appeared to be in successionally advanced settings with relatively high 

 foliage cover; however, this could also be explained by climate. 



b. HERBIVORY: None observed. 



c. FIRE: A large portion of one site (NW Buttress Taylor Butte 017) was 

 within an area that had burned nearly 20 years ago. Ground or crown 

 fire would rarely spread in its habitat under most conditions. It is 

 therefore possible that these plants are adapted to landscapes in which 

 fires maintain and expand potential habitat for them. 



F. LAND OWNERSHIP (MONTANA): Land ownership for the currently known 

 flowering occurrences of Astragalus barrii in Montana is as follows: 



1. U.S. Forest Senice (Custer National Forest)^: 



Stag Rock Knolls (010) 



Fort Howe Ridge (Oil) 



Taylor Butte Rim (012) 



Stag Rock Cliff Tops (013) 



King Creek Well (015) 



Stag Rock Reservoir Ridges (016) 



Otter Creek (031)* 



Horse Creek/Otter Creek (037) 



2. U.S. Bureau of Land Management (Miles City District)^: 



Butte Creek (002) 



^Sites with an asterisk (*) span U.S. Forest Service and private land. 

 ^Sites with an asterisk (*) span U.S. Bureau of Land Management and private lands. 



26 



