EXPERIMENTAL 

 PROCEDURES 



Chromatographic analyses of more than 350 plant specimens are included in this 

 study. The plants chromatographed came from widely occurring populations in Utah, 

 Idaho, Nevada, Wyoming, Colorado, Arizona, Oregon, and British Columbia, and include 

 most species of the section Tridentatae. Attempts were made to collect from a wide 

 variety of sites so that collections would be fairly representative of the distribution 

 of species and subspecies. Although the majority of collections were taken from sites 

 within the Great Basin, many were obtained from populations outside this geographical 

 area. 



Artemisia populations were sampled by collecting foliage from mature representative 

 individual bushes. Naturally occurring and transplanted bushes were sampled. Trans- 

 planting apparently did not affect the chromatographic patterns. Sampled foliage con- 

 sisted of persistent, overwintering leaves from nonf lowering stalks. Leaves on Arte- 

 misia flowering stalks have been reported to give variable results in chromatographic 

 studies (Winward and Tisdale 1969; Brunner 1972") . Early results indicated little 

 seasonal variation in chromatographic patterns from persistent leaves; consequently, 

 foliage was collected during all seasons of the year. Foliage was placed in open brown 

 paper bags and dried at room temperature. 



A modification of the chromatographic methods developed by Alston and Turner (1962) 

 was employed. A mortar and pestle were used to pulverize 0.5 g. of dried leaves. 

 Samples were placed in 30 ml. bottles into which 7.0 ml. absolute methanol had been 

 introduced. Extraction of phenolic substances was carried out at room temperature for 

 24 hours. The extract then was decanted and concentrated by evaporation to 2.0 ml. 



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