Figure 54. — Mountain rub- 

 ber rabbitbrush (C. 



nauseosus ssp. salici- 

 foliusJ growing on 

 Strawberry Ridge on the 

 Utah-Wasatch Co. line 3 

 Utah. 



yellow-green form adapted to sandy areas in the Colorado River drainage. Subspecies 

 hololeucus is a Great Basin foothill and valley form similar to ssp. albiaaulis . It 

 differs from the latter subspecies only in cryptic floral and achene characteristics. 

 Subspecies leiosipermus is a low shrub usually less than a meter in height. It has 

 affinities to ssp. oonsimiUs . It occurs mostly on arid sites in the southern part of 

 the Great Basin. A distinguishing feature of ssp. leiospermus is its glabrous or 

 nearly glabrous achenes. 



A few additional subspecies occur principally outside of the Intermountain area. 

 These include nauseosus (mostly on the western edge of the northern Great Tlains) , 

 mohavensis (southern California) , and turbinatus (Colorado plateau) . 



Chrysothamnus parry i (Gray) Greene (parry rabbitbrush) 



Parry rabbitbrush is a shrubby species somewhat intermediate in height, stem and 

 leaf tomentum, and growth habit between rubber rabbitbrush and low rabbitbrush. Parry 

 rabbitbrush is a low, dense shrub similar in habit to certain forms of C. viscidiflorus. 

 It is usually from 2 to 6 dm in height with numerous spreading to erect flexible 

 branches (fig. 55). Like C. nauseosus, the branches of Parry rabbitbrush are covered 



Figure 55. — Howard rab- 

 bitbrush (C. parryi ssp. 

 howardij growing at 

 Current Creekj Duchesne 

 Co. 3 Utah. 



51 



