Description of the Russian Thistle. 197 



sian cactus, but strictly speaking it is neither 

 a thistle nor a cactus. 



This plant, it is claimed, first obtained a 

 foothold in the United State-s in Bonhomme 

 county, South Dakota, about the year 1873. 

 It is supposed to have been brought in flax- 

 seed from the plains of Russia, where it 

 has been growing increasingly formidable 

 for at least two centuries. So rapid was 

 the spread of the Russian thistle in the 

 United States that it was soon considered 

 a serious menace to successful agriculture 

 in several of the prairie states bordering on 

 the Mississippi and Missouri rivers. It has 

 also made its appearance in states farther 

 to the east, but nowhere is it now so seri- 

 ously regarded as it was a few years ago, 

 though it is still a very troublesome weed 

 in the prairie sections. 



The Russian thistle is an annual. The 

 early leaves of the young plants are smooth 

 and slender, about two inches long, and 

 each is tipped with a spine. Above the 

 early leaves branches grow out which pro- 

 duce many spines, and the number and 

 length of the branches vary much with the 

 attendant conditions of growth. The spines 

 grow in clusters of three, and as the plants 



