distinguish from A. diversifolius , and according 

 to Dorn (1984) , these two species are one (A. 

 diversifolius ) . However, Barneby, the monographer 

 of the North American species of Astragalus 

 (1964) , recognizes them as two species. According 

 to Barneby (1954) , in general A. diversifolius has 

 broader and thinner-textured leaflets, and a 

 broader and shorter pod. Also A. diversifolius 

 occurs in more mesophytic habitats, and does not 

 occur in Montana (Barneby 1964) though it is found 

 in Idaho close to the Montana border. 



At the Helena National Forest site. Astragalus 

 convallarius var. convallarius was found with 

 another Astragalus species, A. flexuosus. This 

 species differs from convallarius in not appearing 

 rush- or broom-like as it has numerous (15-21) , 

 well-developed leaflets. 



Although there are three varieties of Astragalus 

 convallarius , only the var. convallarius is found 

 in Montana. 



D. GEOGRAPHICAL DISTRIBUTION 



Astragalus convallarius 

 var. convallarius 



RANGE: Astragalus convallarius var. convallarius is 

 a Great Basin species which ranges from 

 southeastern Idaho east into southwestern Wyoming 

 and then south to northeastern Nevada, most of 

 Utah, and northwestern Colorado (Barneby 1964) . 

 There are two pop- 

 ulation clusters 

 in Montana: one in 

 the upper Missouri 

 River valley near 

 Helena (Broadwater 

 and Lewis & Clark 

 Counties) at the 

 northern extent of 

 species distribution, 

 and the other south 

 of Dillon close to 

 the Idaho border in 

 Beaverhead County 

 (Figure 5) . 



2. CURRENT SITES: Of the seven known populations in 

 Montana, only one is from the Helena National 

 Forest. This site (EOR# 007) between Beaver Creek 

 and Big Log Gulch in the Helena Ranger District 

 was discovered during the course of the field 



17 



