74 



WEED FLORA OF IOWA 



Extermination. — This weed is usually exterminated by cultiva- 

 tion and may be destroyed by the application of iron sulphate at 

 the rate of 100 pounds to a barrel of water. 



POLYGONACEAE, SMARTWEED FAMILY. 



This family contains the pie plant, canaigre, prince's feather, 

 and buckwheat. 



Curled Dock, Yellow Dock (Rumex crispus L.). 



Description. — A smooth perennial from 3-4 ft. high ; leaves with 

 strongly wavy and curled margins, lanceolate and acute, lower leaves 

 with bases somewhat truncate or inclined to be heart-shaped ; flow- 

 ers collected in dense whorls, extended or prolonged into racemes, 

 entirely leafless above, but below with small leaves ; 6 sepals, the 3 

 outer, herbaceous, leaflike, the 3 inner, larger and somewhat curled, 



Fig. 40. Sour Dock, Curled Dock or Yellow Dock (Rumex crispus). 

 in low grounds, clover meadows, fields, etc. 

 (Photographed by Colburn.) 



Common 



