Fiauve 18. — Shaiiscai^e sai^x-uusri inter-mixed with occasional greasewood i Sarcobatus 

 vermiculatusJ on west side of Sanvete Valley, Sanvete County, Utah. 



Filled utricles have been produced artificially when shadscale pollen was used to 



fertilize pistillate plants of fourwing saltbush. Of the seeds produced by this 



procedure, 7.9 percent were viable (table 1). We hope to produce fertile hybrids 

 between these two species. 



Plummer and others (1957) reported a number of natural hybrids between shadscale 

 saltbush and cuneate saltbush in the Colorado River drainage 16 km (10 miles) south of 

 Emery, Utah, on Utah Highway 10. Apparently, this is a fairly common hybrid in nature 

 and should not be difficult to produce artificially. 



H. C. Stutz and C. L. Pope (personal communication) of the Botany and Range 

 Science Department of Brigham Young University have recently found shadscale occurs 

 as a polyploid series from diploid (2n = 18) to decaploid (2n,= 90). 



Distribution and habitat: Shadscale occurs most often on heavier soils, although 

 it has been found on soil containing as much as 70 percent sand. Soluble salts in 

 these soils vary from 160 to 3,000 p/m and pH from 7.4 to 10.5 (Hanson 1962). 



Shadscale is the dominant plant on over 129,000 km^ (50,000 mi^) from Canada to 

 Mexico at elevations from 460 to 2,135 meters (1,500 to 7,000 feet) (Hanson 1962; 

 Branson 1966). It can be found in nearly pure stands on alkaline soils in the Great 

 Basin and other parts of the West (Benson and Darrow 1944) . Over much of its range, 

 shadscale occurs in mixed stands with species of greasewood {Sai'cobatus') (fig. 18), 

 sagebrush {Artemisia'), hopsage {Grayia) , rabbitbrush (Chrysothamnus) , horsebiush 

 (Tetradymia) , and juniper (Juniperus) . It endures highly alkaline soils better than 

 most of these associates and can be found growing with such halophytes as glassv\'ort 

 iSalicomia') (Hall and Clements 1923) . Bud sagebrush (Artemisia spinescens) is a 



14 



