among Populus tremuloides , along foothills watercourses. It is 

 also in well-drained valleybottom margins of evergreen forest and 

 adjoining meadow. 



T0PCX3RAPHY: In the Sweetgrass Hills it spans a wide range of 

 topography from the base of the buttes to the lower borders of 

 the talus-ringed summits. It was most consistently found on 

 gentle north-facing slopes, but occurred at every aspect over a 

 range of slope angles. The lowermost Sweetgrass Hills 

 subpopulations are at about 4600', almost 2000' lower than the 

 minimum elevation elsewhere in Montana, and in a relatively wide 

 range of settings (Shelly 1989a) . 



SOIL RELATIONSHIPS: Soils are well-drained loams that varied 

 considerably in soil depth, organic matter content and parent 

 material. It was not restricted to the heavy clay loams with 

 which the taxon is associated elsewhere in its range (Shelly 

 1989a) . 



REGIONAL CLIMATE: This taxon depends on moist, stable spring 

 conditions of a cool, temperate climate. It was observed that 

 the Sweetgrass Hills deviate from the surrounding regional plains 

 climate in relatively high cloud cover and precipitation, 

 representing a pocket of suitable climate favorable for this 

 species. It typically occurs in settings of snow accumulation 

 elsewhere in its range. 



SUMMARY: Occurrence of Clavtonia lanceolata var. f lava in the 

 Sweetgrass Hills represents the northernmost record in Montana. 

 It is completely composed of the white flower form rather than 

 yellow form, the two forms now recognized as being genetically 

 identical. Its current treatment as a variety of C. lanceolata 

 will be changed and it will be subsumed in a widespread species 

 of arctic origin. Its local abundance and range disjunction 

 augment the biodiversity picture emerging in the Sweetgrass 

 Hills, though sensitive species recognition is not appropriate 

 for it at this time. 



This report contains the most complete and current available 

 information compiled on the status of Clavtonia lanceolata var. 

 f lava in Montana. This information is to be conveyed to the U.S. 

 Fish and Wildlife Service in reconsidering its status as a 

 possible candidate for designating as threatened or endangered. 



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