A similar but taller species, birchleaf mountain mahogany (C. betuloides) , which 

 occurs quite commonly in the Sierra Nevada Mountains, retains its leaves in the winter 

 The extent to which it hybridizes with true mountain mahogany is not known, but we 

 believe they would cross readily. 



Use: True mountain mahogany is grazed by all classes of grazing animals in the 

 summer and winter and is one of the more valuable winter browse plants of deer. 



Cowania mexicana var. stansburiana (Stansbury cliffrose or cliffrose) 



Stansbury cliffrose is a much-branched evergreen, shrubby or arborescent plant, 

 1 to 6 m tall (fig. 19), and is often resinous and strong smelling. The stems are 

 erect, rather stiff, and have gray, shreddy bark. 



Leaves are clustered along the branchlets and are 12 to 25 mm long, with revolute 

 margins and a five- to seven-toothed apex. They are 1 ight -to-dark green, glandular, 

 dotted above, and more or less white tomentose beneath. 



The fragrant, showy flowers are bisexual or rarely staminate (McMinn 1951). They 

 are solitary, on short branchlets, and approximately 20 mm broad. Flowers are peri- 

 gynous with five persistent sepals and five cream or sulphur-yellow petals. The 

 numerous stamens occur in two series, enveloping 5 to 12 liairy pistils (fig- 20). The 

 fruits are achenes, each about 3 mm long and tailed by a plumose style 25 to 50 mm Ion 

 (fig. 21, 26, 35). 



Flowers bloom from May to June and fruits ripen from July to August. There are 

 often two blooming periods, one in June and another in August. The second blooming 

 is usually dependent on summer storms. The best seed results from the first blooming 

 period, although some seed may be produced in September and October from the later 

 blooms . 



Figure 1 9 . — Large 

 Stansbury cliffrose 

 growing north of Mona, 

 Juab County 3 Utah. 



15 



