WEEDS OF GRAIN AND FORAGE CROPS 51 



been carefully traced. Apparently it was first brought in 

 by immigrants from Russia in the great Northwest, about 

 1873, arid since then it has spread with marvelous rapidity, 

 not only by being blown across long stretches of prairie, 

 but also by means of railroad trains, and probably -in 

 other ways. It has attracted more attention than any 

 other weedy plant of recent introduction, and has been 

 the cause of a great awakening in regard to the whole 

 subject. 



The Russian Tumbleweed is an annual that starts as a 

 slender seedling bearing a general resemblance to a very 

 young pine tree. Its leaves are slender, soft, and velvety. 

 It grows rapidly, however, and toward midsummer takes 

 on a spiny appearance, spreading out to cover an area three 

 or four feet in diameter, with the height nearly as great, 

 and a rounded outline similar to that of our common 

 Tumbleweeds. When the seeds are finally mature and 

 ready to be dispersed, the main stalk breaks off at the 

 surface of the ground and the plant rolls away. It then 

 justifies its German name "Wind Witch," or its Russian 

 name "Leap the Fields." With the impetus given 

 by a violent wind, the plants go rolling and tumbling 

 across the prairies, to be caught in great windrows when an 

 obstacle interferes. As they roll along they drop their 

 seeds by the way, so that the country traversed is likely to 

 become thoroughly infested. 



While the greater part of the weeds that infest grain 

 fields arise from seeds present or introduced, it sometimes 

 happens that when meadow or pasture land is broken up 

 and planted to grain, there is trouble from perennial weeds 

 whose roots or rootstocks remain in the soil. Thus, if a 

 meadow is infested with milkweeds and is planted to oats, 

 the milkweeds will multiply rapidly under the favorable 



