^ Element Name: Thlaspi parvif lorum A. Nels. 



Common Name: Small-flowered pennycress 



Range: Endemic to southwest Montana, northwest Wyoming and 

 central Idaho. In Montana this species is known from Beaverhead, 

 Madison, Park and Silver Dov/ counties. 



Element Rank: G3/S2 



Federal Status: USFS Region 1 Sensitive 



Local Occurrence: I located two populations of I\_ parvif lorum 

 in moist grasslands and meadows on gentle slopes or alluvial 

 terraces in the Moose Town area (Fig. 2). The eastern population 

 occurred in a somewhat drier site and was estimated at 100-1,000 

 plants. The western site was estimated at 1,000-10,000 plants. 

 Associated plant communities are Potentilla f ruticosa / Festuca 

 idahoensis and Potentilla f ruticosa / Juncus balticus . 



Comments: I searched extensively for this species in the Moose 

 Town area, but in spite of large areas of apparently potential 

 habitat, I located only two populations. However, T\_ parvif lorum 

 is inconspicuous unless it is blooming, and it blooms very early 

 and has completely disappeared by mid-summer. Thus, I may not 

 have located all populations in the study area. 

 m Both I\_ parvif lorum sites are subject to livestock grazing. 



The effects of grazing on the species are not known. 



Flement Name: Carex vallicola Dewey 



Comjnon Name: Valley sedge 



Range: Eastern Oregon to southwest Montana and western South 

 Dakota, south to California, Utah and Mexico. In Montana the 

 species is known from Beaverhead, Gallatin, Lewis & Clark, 

 Madison, Park and Silver Bow counties. 



Element Rank: G5/S2 



Federal Status: None 



Local Occurrence: I located one population of C_^ vallicola in 

 mesic high-elevation grassland in the Limekiln Hill area (Fig. 

 3). The population was estimated to be 100-1,000 plants. The 

 associated plant community is Festuca idahoensis / Aqropyron 

 caninum . 



Comments: This small population of C^ vallicola is in an area 

 that has extensive mining exploration. The area is also subject 



m 



13 



