Use. — Because of its scant foliage and stiff branches, stiff sagebrush has little 

 value for browse, except for sheep (Hall and Clements 1923). This species provides 

 important cover on the poor, rocky soils where it grows. It appears to have a wider 

 range of adaptation than is indicated by its present natural range of occurrence, thus 

 giving it potential use in reclamation of disturbed sites. 



Artemisia rothrockii Gray (timberline sagebrush) 



Timberline sagebrush is a consistently low-growing, evergreen, flat-topped shrub 

 from 1 to 8 dm tall (fig. 23). Its appearance in the field closely resembles some 

 forms of mountain big sagebrush. Timberline sagebrush, however, has a more pronounced, 

 consistent tendency to layer and has thicker, darker, more or less viscid leaves, which 

 give the plant a dark green color. 



Leaves on the vegetative branches are often 10 mm broad and 3 cm long (Beetle 

 1960) but range in size from 2 to 51 mm wide and 0.5 to 5 cm long. The lower leaves 

 are mostly broadly cuneate or fan shaped and 3-toothed or lobed (fig. 5d) . The upper 

 leaves, however, may be entire and linear to lanceolate or oblanceolate . The foliage 

 emits a mildly aromatic aroma when crushed. 



Flower heads occur singly or occasionally 1 to 3, in short interrupted spike or 

 racemelike inflorescences. Each head contains 6 to 16, rarely as many as 20, disc 

 flowers. Ray flowers are lacking. The 10 to 14 involucral bracts are often brown or 

 purplish. Achenes are granulif erous . Flowers bloom during August and September. Seeds 

 mature during September and October. Plantings of this sage in valley lowlands of cen- 

 tral Utah have bloomed profusely, but none of the plants produced mature seed. 



Hybridization. --Artemisia rothrockii occurs in diploid (2n = 18), tetraploid 

 (2n = 36), hexaploid (2n = 54), and octoploid (2n = 72) forms (Ward 1953; McArthur 

 and Plummer 1978) . Beetle (1960) suggests this species may be of hybrid origin from 

 A. cana, which it resembles in its strong tendency to layer, large heads and conspic- 

 uous bracts, and A. tridentata , which it resembles in leaf shape, general habit, and 

 habitat. Our discovery (McArthur and Plummer 1978) that at least some Rocky Mountain 

 forms are diploid does not support Beetle's hybrid ancestry contention. However, the 

 diploid Rocky Mountain material may be an undescribed taxon rather than bona fide 

 A. rothrockii. 



23 



