B. GEOGRAPHICAL DISTRIBUTION 



1. Species range: Limited to western Montana, east central 

 Idaho, and northcentral Colorado (Hitchcock and Cronquist 

 1973) . 



2. Montana distribution: Previously known from ten sites in 

 Beaverhead and Madison Counties, including one site in the 

 study area. 



3. Occurrences in the study area: Eight new populations were 

 found in the central and southern parts of the study area, in 

 the Muddy Creek basin and basins of other tributaries of Big 

 Sheep Creek. 



C. HABITAT 



Within the study area, this species occurs at elevations 

 ranging from 6,800 to 7,100 ft. in moist alkaline meadows. 

 Vegetation at these sites is dominated by shrubs (Artemisia 

 arbuscula, Artemisia cana, and Potentilla fruticosa) or by 

 graminoids (Descbampsia caespitosa, Poa pratensis , and Juncus 

 balticus) . 



D. POPULATION BIOLOGY 



Populations are large with numbers estimated from over 100 to 

 over 10,000 aerial stems. 



E. MANAGEMENT CONSIDERATIONS 



A. leptaleus is quite common in nearly all of the alkaline 

 meadows visited in the study area, and it is quite widespread 

 in southwest Montana. It has probably been overlooked because 

 of its diminutive size and growth habit. The plant was common 

 even in meadows that were heavily grazed and trampled. For 

 these reasons it is recommended that this species no longer 

 be further considered for BLM special status designation or 

 state tracking. 



Astragalus scapboides (Jones) Rydb. 

 Bitterroot milkvetch 



A. DESCRIPTION 



1. General description: See the genus description (page 9) . 

 These are erect perennials with large white-yellowish flowers 

 and stalked fruits. 



2. Technical species description (quoted from Hitchcock and 

 Cronquist 1961) : 



Sparsely strigillose perennial with a taproot and 

 branched crown; stems several, stout, ascending to erect, 

 2-6 dm tall; leaves 10-25 cm long; stipules lanceolate, 



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