on a global scale due to a limited range, but it is 

 critically imperiled within the state due to extreme 

 rarity (Heidel 1994). In Wyoming, the species is ranked 

 S3 (Fertig 1994), however it may be ranked too high 

 (Fertig, pers. comraun.); it is known from a fair number 

 of collections, but these are all from a relatively 

 narrow range. 



C. GEOGRAPHIC DISTRIBUTION 



1. Species range: The species is known only from Park 

 County in northwestern Wyoming (Evert 1983, Dorn 1992) 

 and from Beaverhead County, Montana. 



2. Montana distribution: Lomatiurn attenuatum was first 

 discovered in the state in 1993 by Peter Lesica on BLM 

 land in the Tendoy Mountains (Vanderhorst and Lesica 

 1994). Additional populations were found in 1994 in the 

 Tendoys and to the north near Bannack (Vanderhorst 

 1995b) . 



3. Occurrences in the Tendoy Mountains: The species was 

 found on the Beaverhead National Forest on a slope above 

 Sourdough Creek (004). An Element Occurrence Record and 

 map showing the precise location of the population is 

 included in Appendix D. In addition, three populations 

 are known from BLM land in the Tendoys (Figure 2). 



D. HABITAT 



1. Associated vegetation: In the Tendoys, Lomatiurn 

 attenuatum grows in limber pine (Pinus flexilis) and 

 mountain mahogany (Cercocarpus ledifolius) communities. 

 The limber pine forest of the population site on the 

 Beaverhead National Forest was sampled by an ecodata plot 

 (NHMT020194SC005) . There was 40% canopy coverage by 

 Pinus flexilus and Pseudotsuga menziesii . Shrubs, which 

 contributed a total of 10% coverage, included Juniperus 

 communis^ Artemisia tridentata, and Ribes cereum. 

 Graminoids, having a total coverage of less than 30%, 

 included Leucopoa kingii, Elymus spicatus , Festuca 

 idahoensis, Poa cusickii , and Carex rossii. There were 

 24 forbs in the plot, but only Phlox caespitosa had a 

 coverage greater than 1%. 



2. Topography: In Montana, Lomatiurn attenuatum occurs on 

 mountain and canyon slopes ranging in elevation from 

 6,200 to 8,500 feet. The Beaverhead National Forest site 

 is a steep, south facing, upper slope just below the 

 crest of the range, and is the highest elevation known 

 for the species in the state. 



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