Twenty-five vl of this extract were added to duplicate 9-inch squares of UTiatman No. 3 

 MM chromatographic grade filter paper. The solvent system for the first dimension 

 was n-butanol : acetone : water (4:1:3) and for the second dimension, acetic acid: water 

 (15:85). Chromatograms were viewed under longwave ultraviolet light before and after 

 exposure to ammonia fumes in order to note the appearance and color changes of result- 

 ing spots. Each spot was given an arbitrary number for identification purposes and the 

 value computed for both dimensions of the finished chromatogram. 



^ _ Distance of spot from starting point 



f Distance of solvent front from starting point 



The value of a given spot is then expressed as : 



R^ = R_p(first dimension) /R^(second dimension). 



Thin-layer plates coated with silica gel G were photographed to illustrate the 

 difference among groups of big sagebrush. Each plate was divided into three 6- by 

 20-cm. sections and the base of each section was streaked with approximately 200 pi of 

 extract. Chromatograms were developed in a single direction using n-butanol : acetone : 

 water (4:1:1) as the solvent system. Fol lowing, development , the plates were exposed to 

 ammonia fumes, allowed to dry, and photographed under ultraviolet light (Kodachrome 11 

 film, ASA 25, and a 2B filter). 



Identification of the constituents of the methanol extracts is beyond the scope of 

 this paper. Shafizadeh and Melnikoff (1970) report that phenolic extractives of 

 Artemisia tridentata subsp. vaseyana leaves are mainly coumarins with various side 

 chain substituents . 



4 



