E. HABITAT: The sites where populations of A. 

 fecunda occur are distinguished by sandy or 

 gravelly, light-colored, highly calcareous soils, 

 derived from metamorphosed calc-silicate parent 

 materials. These sites are found along small to 

 large drainages at the edges of mountain uplifts, 

 where these parent materials have been exposed by 

 erosion. 



Arabis fecunda populations occur in the sagebrush- 

 grassland zone at locations in Ravalli, Silver Bow 

 and Beaverhead counties. Additionally, some 

 populations in Beaverhead County occur in dry 

 Douglas-fir and lodgepole pine forest zones on 

 open calcareous slopes. The sites range from 

 4,600 to 8,000 feet in elevation. Total 

 vegetation cover at these sites is often low. 



1. ASSOCIATED VEGETATION: Arabis fecunda 



populations occur most frequently in shrub- and 

 grasslands, often near open, sparse stands of 

 Pinus ponderosa (ponderosa pine) , Pseudotsuga 

 menziesii (Douglas-fir) , or Juniperus scopulorum 

 (Rocky Mountain juniper) . The common native 

 species associated with A. fecunda at one or more 

 sites include: 



Achillea millefolium (common yarrow) 



Aqropyron spicatum (bluebunch wheatgrass) 



Artemisia friqida (fringed sagewort) 



Artemisia tridentata (big sagebrush) 



Astragalus miser (weedy milk-vetch) 



Carex f ilifolia (thread-leaved sedge) 



Castilleia pallescens (palish indian-paintbrush) 



Cercocarpus ledifolius (curley-leaf mountain 



mahogany) 



Chrysopsis villosa (hairy goldenaster) 



Crepis spp. (hawksbeard) 



Crvptantha celosioides (northern cryptantha) 



Draba oligosperma (few-seeded draba) 



Erigeron compositus (cut-leaved daisy) 



Eriogonum umbellatum (sulphur buckwheat) 



Festuca idahoensis (Idaho fescue) 



Gilia spicata (spicate gilia) 



Haplopappus acaulis (cushion goldenweed) 



Haplopappus armerioides (thrifty goldenweed) 



Koeleria cristata (Junegrass) 



Linum perenne (blue flax) 



Lithospermum ruderale (wayside gromwell) 



Mertensia oblongifolia (oblongleaf bluebells) 



Orvzopsis hymenoides (indian ricegrass) 



Oxytropis lagopus (haresfoot locoweed) 



