officinalis) and a weedy native species called Venus looking glass (Triodanis 

 perfoliata) which now dominate the habitat. Such invasions seem to 

 correspond with hea\7 grazing in directly adjoining habitat. 



RECOMMENDATIONS FOR MAINTAINING VIABLE 

 POPULATIONS 



a. PROTECTION OF NATURAL HABITATS THAT CURRENTLY 

 SUPPORT LARGE POPULATIONS: Several sites with large 

 populations appear to be buffered against drought conditions (Biddle 

 School Section 007; King Creek Well 015 and Taylor Butte Rim 012). 

 Recognition of these sites as natural areas or as botanical special 

 interest areas with Barr's milkvetch elevated to a management priority 

 would contribute to long-term viability of the species in the state. 



b. REGULATION OF ACTIVITIES DIRECTLY ADJOINING 

 NATIVE HABITATS THAT SUPPORT LARGE 

 POPULATIONS: Proposed disturbances within or near any of these 

 documented populations should be preceded by detailed survey of the 

 populations in these areas. Further, mitigation measures should be 

 developed to reduce or to eliminate the impacts of management 

 activities. It is appropriate to address this species in allotment and 

 weed management plans and in quarrying permits. 



RECOMMENDATIONS FOR FURTHER ASSESSMENT: In order to 

 characterize its status and distribution on the District, revisits to the seven sites 

 of putative Astragalus bairii in vegetative condition are needed. Survey work 

 is also recommended for public lands elsewhere in the two counties, 

 concurrently with extended information-gathering on Ipomopsis congesta var. 

 pseudotypica when it is in flower (see separate discussion for this taxon). 



SUMMARY 



Astragalus barrii is one of few species endemic to the Great Plains. Most of the species in the 

 Great Plains flora have extensive ranges (Great Plains Flora Association 1986). The 8 

 occurrences of ^. barrii on the Ashland District represent the only public lands occurrences in 

 Montana that are covered under a sensitive species program. Recognition as a sensitive 

 species should continue; taxonomic confirmation at the seven additional sites is of prime 

 importance. 



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