Four populations were found only in vegetative condition during this study in 

 A. barrii habitat. Visits to these sites during the flowering season are needed. 

 Bart's milkvetch is known to bloom early, from April into June. The 

 phenology of A. hyalinus in the study area is not as well understood. Although 

 thought to be an early-season species, populations that were strictly vegetative 

 in the first half of June were flowering in early July (Schmoller pers. comm.). 

 The small-flowered population was in early flower on June 2 1 . The unusually 

 wet and cool season may explain the delayed flowering of .4. hyalinus. 



GEOGRAPHICAL DISTRIBUTION 



1. GLOBAL RANGE: A regional endemic, A. barrii is known from 

 southeastern Montana, southwestern South Dakota, and northeastern 

 Wyoming. 



2. STATE RANGE: In Montana, A. barrii is currently known from 29 

 occurrences in Powder River (18), Bighorn (3), and Rosebud (7) counties 

 (Figure 6). In addition, there is one historical record from Carter County that 

 has never been relocated. There are also 7 Powder River County sites that are 

 not included in the tallies because they are held in question. 



3. STUDY AREA DISTRIBUTION: The 1 5 kno\\Ti sites are depicted in 

 Figure 6, including 2 new records of ^. barrii documented during this study. 

 The presence of A. hyalinus in the study area provides basis to question all 

 previous determinations based on plants in vegetative condition, due to the 

 similarity of the two species during this stage. Information on three previously 

 recorded populations in \'egetative condition and four new records in 

 vegetative condition remain in the database. These seven records are not 

 included in the tally of 15 sites mentioned above, though they are shown on the 

 Figure 6 distribution map and included among the printouts (Appendix C). 

 They require revisits to make definitive distinction between A. barrii and A. 

 hyalinus. 



Study area distribution of the eight known population sites is centered around 

 the Otter Creek drainage. The seven additional occurrences whicli warrant 

 confirmation represent extensions northward and southward, and are important 

 in understanding District distribution. 



Survey was not conducted outside of the Ashland District, though there is 

 potential habitat on lands south of Ashland on the east side of the Tongue 

 River and southwest of Ashland on the west side of the Tongue River (on the 

 Northern Cheyenne Indian Reservation). 



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