Figure 22. — Giant arborescent 

 form of antelope hitter- 

 brush growing northeast 

 of Mt. Pleasant J Sanpete 

 County, Utah. This 

 population has obviously 

 received introgression 

 from cliffrose. 



Figure 24. — Antelope bitter- 

 brush showing adventitious 

 rooting along ground level. 



Figure 2 2. --Comparison of 

 achenes of the bitter- 

 brush-cliff rose complex: 

 (1) typical bitterbrush 

 receptacles with one or 

 two achenes; (2) crowded 

 bitterbrush receptacles 

 with five to seven 

 achenes; (2) typical 

 bitterbrush X cliffrose 

 hybrid receptacles each 

 with two or three ■ : 



achenes with short 

 plumes; (4) typical 

 cliffrose receptacles . 

 each with four or five 

 plumed achenes. 



27 



