Fage No. 



39a. Plants freely branching shrubs up to 

 2 m; leaves 1.5 to 4 cm long, deeply 

 divided into 3 linear lobes, each 

 less than 1 mm wide; occurs on dry, 

 well-drained soils from 900 to 1,800 

 m from British Columbia south to 

 northern Nevada, northern Utah, and 



western Montana A. tripartita 



ssp. tripartita 35 

 [tall threetip sagebrush) 



39b. Plants dwarf shrubs with decumbent, 

 often layering branches; leaves up 

 to 3 cm long, deeply divided into 

 linear lobes 1 mm or more wide; 

 occurs on rocky knolls from 2,430 

 to 2,740 m in central and south- 

 eastern Wyoming to southern Oregon 



A. tripartita 



ssp. rupicola 35 

 (Wyoming threetip sagebrush) 



36b. Leaves not silvery-canescent , narrowly 

 lanceolate to broadly cuneate or fan- 

 shaped, typically 3-toothed or lobed 

 (upper leaves may be entire) . 



40a. Plants low-growing, flat-topped shrubs up to 



8 dm high; leaves somewhat viscid; heads occur- 

 ring singly or occasionally up to 3 arranged 

 in short interrupted spike or racemelike in- 

 florescences; heads large with up to 20 disc 

 flowers each; occurs in high mountainous areas 

 of central Colorado, western Wyoming, Utah, 

 central Sierras of California, and Carson Range 



of Nevada A. rothrockii 23 



(timberline sagebrush) 



40b. Plants ranging from dwarf to tall, arborescent 

 forms up to 4.5 m; leaves not viscid; inflores- 

 cences of numerous heads arranged into leafy 

 panicles; heads smaller with 3 to 8 disc flowers; 

 most widespread and common shrub of western North 



America A. tridentata 26 



(big sagebrush) 



41a. Plants uneven-topped shrubs with flowering 

 stalks arising throughout the crown; leaves 

 narrowly lanceolate to cuneate; odor of 

 crushed leaves pungent. 



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