DESCRIPTIVE MANUAL 



115 



Fig. 64 A 



Figure 64B 



Fig. 64-A. Trichomes or plant hairs from stem of pigweed. 

 (Drawing by Charlotte M. King.) 



Fig. 64-B. Distribution of Pigweed. 



Chemical composition, — According to the University of Minnesota 

 the composition is as follows :* 



Tumbleweed (Amaranthus graecizans L.). 



Description. — A smooth, pale green much-branched annual ; at 

 maturity a spherical mass, which separates easily from the root ; 

 leaves oblong-spatulate or ovate ; small flowers greenish, inconspicu- 

 ous, polygamous, several together in small axillary clusters, small 

 and pointed. 



Distribution. — Common in North America especially from Ohio 

 westward. In waste grounds. The detached leafless plants may 

 be seen rolling over fields. 



Extermination. — Easily exterminated by cultivation. 



*Bull. Minn. Agr. Exp. Sta. 11, by Harry Snyder. 



