786 



MANUAL OF POISONOUS PLANTS 



or pink; disk flowers perfect, fertile; corollas yellow and S-lobed; receptacle 

 nearly flat; achenes oblong or obovate, slightly compressed; pappus wanting. 



About 75 species mostly of the Old World. The yarrow (Achillea Ptar- 

 mica) occasionally cultivated. 



Fig. 451. Yarrow (Achillea Millefolium). Structure of flower, a, stigmas; b, papillae; 

 c, style, pollen; d, single flower; e, f, g and £, flowers in different stages. (MiiUer). 



Achillea Millefolium L. Yarrow. 



Perennial herb from 1-2 feet high; simple stems; leaves twice pinnately 

 parted, consisting of crowded linear divisions ; flowers in compound flat-topped 

 corymbs ; heads many-flowered, radiate ; rays 4-5, white ; scales of the involucre 

 with scarious margins ; receptacles chaffy ; disk flowers small, tubular ; achenes 

 oblong, flattened; pappus none. 



Distribution. A common weed from the Atlantic to the Pacific. In the 

 East it is found in old fields and dry hills and is abundant in open parks and 

 rocky dry soils in the Rocky Mountains up to the timber line. It is native also 

 to Europe, where it is used as an ornamental plant. Sheep will eat' the weed. 

 The form with rose-colored ray flowers is frequently cultivated. 



Poisonous properties. The alkaloid achillein C^^H^^T^^O^^ has been isolated 

 from the plant. Millspaugh describes the action of the drug as follows: 

 "Yarrow seems to have a decided action upon the blood vessels, especially in 

 the pelvis. It has been proven to be of great utility in controlling hemorrhages, 

 especially of the pelvis, viscera, where hemorrhage is caused by it. Its common 



