major cause (see Lesica in review). Damage to the foliage A^ 

 scaphoides by insects is probably reducing the vigor of the 

 affected plants. 

 3. Potential threats— The paucity of large populations makes this 

 species more vulnerable to extirpations or loss of genetic 

 variability if enviromental fluctuations should result in the 

 destruction of one of the few important populations. Since A^ 

 scaphoides often occurs on lower slopes above drainages - 

 topographic positions which are frequently favorable to road 

 construction, future road construction may threaten populations 

 of this species. 



B. Overutilization for commercial, sporting, scientific, or 

 educational use— No threats known. 



C. Disease predation or grazing—See existing threats and Lesica 

 (1985). 



D. Inadequacy of existing regulatory mechanisms 



1. Past threats—None known. 



2. Existing threats—Allowing grazing in early spring may be 

 adversely affecting A. scaphoides by causing some predation and 

 trampling. 



3. Potential threats— None unknown. 



E. Other natural or man-made factors— None known. 

 II. Summary and Recommendations 



12. General assessment of vigor, trends and status— Based on previous 

 collecting records and five days of field searching, it appears that 

 Astragalus scaphoides is generally limited to a small area of 

 southwestern Beaverhead Co., MT and the Lemhi River drainage between 

 Leadore and Tendoy in Lemhi Co., ID. [ Futhermore, populations of more 



14 



