334 



Kansas State Board of Agriculture. 



shape. The plant flowers in June and ripens its seeds in July or a little 

 later. It is commonly found in waste places, clover and alfalfa fields, 

 and meadows. 



Curled dock is readily eradicated by short rotations and cultivated 

 crops. Where this is impracticable, hand pulling when the ground is soft 

 and wet is the best way to get rid of it. Avoid sowing the seed with crop 

 seeds. 



SHEEP SORREL or SOUR DOCK (Rumex acetosella L.). Sheep sorrel 

 is a perennial weed with shallow-running rootstocks, from which it sends 

 up new plants in all directions. It rarely grows taller than eight or ten 



inches, otherwise resembling the 

 other docks in general character- 

 istics. It produces an abundance of 

 small triangular seeds during July, 

 August and September. This is not 

 a very common weed in this section 

 as yet, but is sure to become so, be- 

 cause its seeds are so abundant in 

 commercial grass and clover seeds. 

 Sheep sorrel grows best in thin or 

 worn-out meadows and clover fields. 

 Breaking the meadow and growing 

 some cultivated crop will usually 

 subdue the weed. The soil should 

 also be limed. 



RUSSIAN THISTLE (Salsola kali 

 tenuifolia, G. F. W. Mey). This is 

 an annual weed which is supposed 

 to have come from Russia in some 

 imported flaxseed. The plant is from 

 one to three feet high and sometimes 

 has a diameter of six feet. It 

 branches very profusely, giving it a 

 bushy appearance, sometimes almost 

 spherical. The plant is light green 

 in color, has a small white taproot, 

 and small leaves tapering down to 



sharp spines. Because of these spines it is called a "thistle," although it 

 does not belong to the true thistle family. The plant matures its seeds in 

 August. The seeds are spiral shaped, covered with a thin gray hull. It 

 is estimated that a large plant will produce from 100,000 to 200,000 

 seeds. The seed is found in commercial flax and clover seeds, but more 

 especially in western-grown alfalfa seed. Its rapid spread is due partly 

 to this fact and partly to the fact that the plant is a so-called tumbleweed. 

 In autumn the weed breaks away from its stem and is carried for long 

 distances by the wind, scattering seeds as it goes. 



Prevent Russian thistles from maturing by cultivation or harrowing. 

 The plants are easily destroyed while small. If allowed to mature they 



Fm. 279. Rough pigweed. 



