where the vegetation is a mingUng of dominants from sagebrush steppe (ARTTSW/ELYLAN) and 

 STICOM/CARFIL grassland types. Smaller populations of Astragalus racemosus were found in 

 shrub dominated communities, including Artemisia tridentata ssp. wyomingensis/Elymus lanceolatus 

 (ARTTSW/ELYLAN) and Sarcobatus vermiculatus/Elymus lanceolatus (SARVER/ELYLAN) 

 habitat types. The elevation ranges from 3000-3760 ft. 



SPECIES BIOLOGY: The species is considered short-lived (Barr 1983). The largest population 

 documented to date in Montana was found in 1997 on BLM and private land above South 

 Cottonwood Creek. It was estimated to consist of about 2,000 plants covering over 40 acres, and 

 included many extremely robust plants with high fruit production judging from the quantity of 

 maturing fruits observed in mid-July. Relatively high numbers (about 100 plants) were also observed 

 at East Finger Buttes but at the time of survey in mid-August all plants observed were vegetative or 

 had naked flower stalks, with no fruits, indicating either fruit dispersal or flower abortion. Several 

 fruiting plants were observed along the roadside near Three Peaks, but the occurrence is on private 

 property and was not completely surveyed. White-flowered plants with immature fruits were also 

 observed at the northwestern end of the block of BLM-administered land lying southeast of Chalk 

 Buttes; but verification was not possible. Relatively few plants were seen at the other 3 locations 

 surveyed in 1997, but these were sometimes widely scattered across large areas of potential habitat, 

 making complete survey difficult. Most of the plants in these small populations were vegetative and 

 identification hinged on encountering a single reproductive plant. 



OTHER COMMENTS: Astragalus racemosus accumulates selenium and may cause poisoning of 

 livestock. The Great Plains Flora Association (1988) reports that the species is rarely eaten by 

 livestock, however, other species of Astragalus are reported to cause addiction leading to "locoism". 

 No browsed plants were observed but all populations found were in good condition rangelands 

 without evidence of recent livestock use. The site of the largest A. racemosus population has 

 unusually high forb diversity and high cover by green needlegrass (Nasella viridula) indicating 

 excellent range condition for the particular range site. It is possible that allotment ranchers keep 

 livestock away from areas that are known to have selenium soils or time the season of use to avoid 

 poisoning effects. The range literature does not indicate whether y4. racemosus is an increaser or 

 decreaser under grazing. The fact that its largest knovm numbers are in noteworthy range condition, 

 and that this is a species of concern to all livestock operators, means that it warrants range 

 management attention if not a watch status. 



The number of new occurrences documented in the course of this study provides evidence for 

 changing its state status from SI to S2. Its status would be changed again if additional occurrences 

 are found or if it increase with grazing in Montana. 



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