3. SOIL RELATIONSHIPS: Lesquerella klausii is 



primarily restricted to sparsely vegetated 

 gravelly or rocky slopes often with poor soil 

 development. The species occurs most consistently 

 in the Big Belts on loose platy shale, but is also 

 found on limestone, argillite, and quartz-derived 

 substrates (adapted from Shelly 1988) . 



4. REGIONAL CLIMATE: In general the climate of west- 



central Montana is classified as cool, dry, and 

 continental, with locally greater amounts of 

 precipitation in the mountains. The two closest 

 weather stations to populations of Lesquerella 

 klausii in the Big Belt Mountain are at Holter Dam 

 and Helena Regional Airport. The Holter Dam 

 station at an elevation of 3487 feet is about 8 

 miles northwest from the closest Big Belt Mountain 

 L. klausii site. For the period of 1951-1980, the 

 mean annual precipitation at Holter Dam was 12.02 

 inches, the mean January temperature was 24.8°F, 

 and the mean July temperature was 69.9°F (U.S. 

 Department of Commerce 1982.) The Helena Regional 

 Airport site at an elevation of 3828 feet is about 

 13 miles southwest from the closest site of L. 

 klausii in the Big Belt Mountains. For the period 

 of 1951-1980, the mean annual precipitation at the 

 Helena Regional Airport was 11.37 inches, the mean 

 January temperature was 18.1°F, and the mean July 

 temperature was 67.9°F (U.S. Department of 

 Commerce 1982) . 



F. POPULATION DEMOGRAPHY, BIOLOGY AND SPECIATION 



1. PHENOLOGY: Lesquerella klausii flowers from early 



May to early July, depending upon climatic 

 conditions and elevation. Peak flowering however 

 at most sites is in late May and early June. A 

 few flowering individuals have been observed in 

 September and October, during warm periods, but 

 probably this does not result in any substantial 

 seed set. Fruiting occurs primarily from mid-May 

 to July, and seems to be very vigorous during peak 

 periods (adapted from Shelly 1988) . 



2. POPULATION SIZE AND CONDITION: Populations of 



Lesquerella klausii range in size from less than 

 20 to more than 3000 individuals. Populations may 

 contain up to nine subpopulations. The average 

 number of individuals in a population is 

 approximately 650. At the end of the 1987 field 

 season, the total number of plants observed was 

 approximately 17000-18000. (Adapted from Shelly 



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