DESCRIPTIVE MANUAL 



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Wallace's Farmer suggests the following treatment: "Russian 

 thistle is easily controlled by cutting it off just below the surface of 

 the ground before it seeds in August. It has not proved a dangerous 

 weed east of Mississippi river." 



CHEMICAL COMPOSITION. 



AMARANTHACBAE, PIGWEED FAMILY. 



This family contains few economic plants. Some, like the cock's- 

 comb, are grown for ornamental purposes. 



Pigweed, Redroot (Amaranthus retro flexus L.). 



Description. — ^A roughish, more or less pubescent annual ; 3-5 ft. 

 tall ; leaves ovate or rhombic-ovate, undulate ; long-margined petiole, 

 entire ; flowers in thick spikes crowded in a stiff or bunchy, spiky 

 panicle; bracts subulate, longer than the mueronate or obtusely- 

 tipped sepals. 



Distribution. — ^A weed throughout North America, especially east- 

 ward ; abundant in every county in the state. 



Extermination. — ^Frequently distributed with clover seed; sow 

 clean clover seed in a clean field. Easily exterminated by cultiva- 

 tion. 



Fletcher and Clark recommend as follows: "When embedded in 

 the soil, the seeds retain their vitality for several years, though prob- 

 ably not more than five in a moist soil, and produce seedling plants 

 only when brought by cultivation within about two inches of the 



surface." 

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