WESTERN YARROW 



Achillea lanulosa Nuttall 



Western yarrow is such a common plant that we usually pass it by 

 without appreciation of its beauty. Growing everywhere, and espe- 

 cially in neglected places, its white heads and feathery foliage are known 

 to everyone. The crushed leaves and flowers have a pungent and some- 

 what irritant odor, which sometimes causes sneezing. Forms in which 

 the heads have pink instead of white rays are not uncommon in the 

 Rocky Mountains. A closely related species of very similar appearance 

 is a weed in fields and waste places in the eastern United States. The 

 genus name of these plants was given in commemoration of Achilles. 



Western yarrow ranges from Oklahoma to Mexico and California, 

 and northward to Quebec, Ontario, Michigan, and Yukon. 



The specimen sketched was obtained in the valley of the Red Deer 

 River, twenty miles north of Lake Louise, Alberta, Canada, at an alti- 

 tude of 6,700 feet. 



PLATE 151 



