SUMMARY 



Bureau of Land Management holdings in the Horse Prairie Creek 

 drainage were surveyed for proposed sensitive and watch plant 

 species (USDI Bureau of Land Management 1993), and for 

 prospective sensitive and watch plant species currently tracked 

 as Montana plant species of special concern (Heidel 1994). There 

 are now 17 populations of seven of these taxa known from BLM land 

 in the study area. Of the seven, Bitterroot milkvetch 

 (Astragalus scaphoides) and Lemhi beardtongue (Penstemon 

 lemhiensis) are currently proposed sensitive species. Railhead 

 milkvetch (Astragalus terminalis) and an undescribed bladderpod 

 (Lesquerella sp. novum I) are currently proposed watch taxa, 

 however, sensitive status is recommended for railhead milkvetch 

 at this time. Chicken sage (Sphaeromeria argentea) has no 

 currently proposed status, but is now recommended to be added to 

 the BLM list of watch plants. Two taxa, limestone larkspur 

 (Delphinium bicolor ssp. novum) and rock-tansy (Sphaeromeria 

 capitata) have no proposed or recommended BLM status, and will no 

 longer be actively tracked by the Montana Natural Heritage 

 Program but will be retained on lists of state endemics and 

 species of limited distribution. A total of 329 vascular plant 

 taxa in 52 families were identified in the study area. Twenty 

 nine of these species are adventive from Eurasia. 



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