CHARACTER MEASURED STANFORD MATHER TIMBERLINE 



*(x) = mean measurement. 



Before commenting on the results given in the above table, 

 some explanation must be given. In nature, the plants oi Achillea 

 native to coastal areas grow actively all year round. They occur 

 in an area which has cool, foggy summers and cool, rainy winters. 

 Frosts are uncommon. Because of frequent exposure to sea winds, 

 many of the coastal plants are dwarfed in stature. In contrast, 

 plants oi Achillea native to the valley areas grow rapidly during 

 the wet season of winter, and become dormant with the onset 

 of drought in the late spring. The plants that occur naturally at 

 Mather generally become dormant in the winter because of the 

 cold weather, although plants from slightly lower elevations are 

 winter-active just as are the valley plants. Plants that occupy al- 

 pine areas (such as Big Horn Lake) are dormant during the long, 

 cold winters and during much of the winter-time are covered by 

 heavy layers of snow. Such plants grow and flower only during 

 the short summer months after the snow has left the ground. In 

 nature, therefore, ylc/i///efl shows a diversity of responses which 



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