41 



HABITAT: Lesquerella pidchella is a calciphilic species which occupies harsh habitat under low 

 competition. In the study area it is restricted to limestone outcrops of the Madison Group in north-south 

 bands centered around Bannack. Note: This is not the only Madison Group outcrop in the study area, 

 and in the extensive Madison Group dolomite outcrops around Henneberry Ridge, only the common 

 bladderpod species, Lesquerella alpina, has been found. 



It spans a 6200-7590 ft range of elevation in the study area, extending upward into lower elevations of 

 the adjoining Beaverhead National Forest. It is also at subalpine elevations of the same Pioneer 

 Mountains area, and known from a single subalpine area in the Centennial Mountains which is from 

 quartzite rather than limestone. Its subalpine elevations range from 8600-9200 ft. This bimodal 

 distribution in elevation zone may reflect its preference for open habitats under low competition. The 

 following habitat description focuses on the foothills habitat of the species as found in the study area, 

 which is typical for the foothills habitat of the species in general. Description of the subalpine habitats 

 of the species is summarized briefly at the end. 



In the study area it occupies some of the most arid, exposed microhabitats on gravelly, shallow substrate 

 over bedrock. It is often on mid and upper slopes, with the angle of slope and the aspect depending on 

 local outcrop variables. The settings tend to be sparsely-vegetated pockets within scrub and grassland 

 communities of the foothills. Local dominant is Agropyron spicatum, with or without Cercocarpus 

 ledifoUus (Appendix D-13). Tree cover of Pinus flexilis is patchy and restricted. 



A representative list of species commonly occurring with it include: 



Achillea millefolium 

 Agropyron spicatum 

 Allium textile 

 Arenaria kingii 

 A rtem is ia frigida 

 Aremisia tridentata 

 Carex rossii 

 Castilleja pallescens 

 Cercocarpus ledifoUus 

 Chaenactis douglasii 

 Delphinium bicolor ssp. novum 

 Douglasia montana 

 Draba oligosperma 

 Erigeron t^veedyi 

 Gilia congesta 

 Gutierrezia sarothrae 

 Haplopappus acaulis 

 Juniperus scopulorum 

 Linum lewisii 

 Lesquerella alpina 



