WEEDS OF SPECIAL CROPS 



53 



in the West and is quite easily recognized by its peren- 

 nial habit and its long leaves, which are close to the 

 ground. The flower stalk is groove-angled and from one 

 to two feet long. It bears a cylindrical spike of flowers 

 somewhat like the common dooryard plantain, but much 

 shorter. Like many of our other troublesome weeds it 

 is a native of Europe. 



Another European vagrant, the 

 sheep sorrel (Rumex Acetosella), is 

 widely distributed in the country. 

 The fact that this weed spreads freely 

 by its running roots accounts for its 

 appearance in mats. There is a widely 

 prevalent opinion that ground on 

 which it occurs lacks lime; but this 

 is far from being the fact, since the 

 weed is very common in soils which 

 contain large quantities of calcareous 

 matter. 



An ally of the preceding species is 

 the curled dock (Rumex crispus). 

 This pestiferous plant, widely dis- 

 tributed throughout the northern 

 states to the Pacific coast, does much 



injury in meadows and pastures. The ,^ g '^' whitew f ed 

 ..-, ... ,, (Engeron ramosus) a 



best method of destroying it IS to pull common weed in tim- 



it up by twisting the root and then oth y and clover mead- 

 removing it by a sudden pull or jerk. ^ (C M^g? 

 Several other species of dock are 

 common in low meadows, among them being the smooth 

 dock (Rumex altissimus). 



Sneezeweed (Helenium autumnale) is extremely com- 

 mon in low ground in many portions of Iowa. This weed 

 has sometimes caused much alarm among stockmen, as 

 it is poisonous. In the South the narrow-leaved species 

 (H. tenuifolium) is abundant. 



