- 4- 
tragas seems to have developed on the plains of southeastern Russia, 
where the conditions are verv similar to those of the great Plains 
region of the United States. For many years it has been a des¬ 
tructive weed in the barley, wheat, and flax regions of southeastern 
Russia, and the cultivation of crops has been abandoned over large 
areas in some of the provinces near the Caspian Sea. No effectual 
methods of exterminating the weed are known in Russia. Sheep, 
pasturing on the young plants, aid materially in keeping the thistle 
in check, but it is continually growing more troublesome and ex¬ 
tending to new territory. 
“ The plant was first introduced into the United States in 1873 
or 1874, in flaxseed brought from Russia and sown near Scotland, 
Bonhomme County, S. Dak. The land there is somewhat hilly, 
and corn is the chief crop raised, so that, owing to the wooded 
ravines and the standing cornstalks, the Russian thistle was at first 
slow in spreading. In 1877 it first appeared in Yankton County, 
east of Bonhomme, and five years later it had spread to the counties 
to the north and west of Bonhomme. It continued gradually to 
cover new territory until 1888, when it had infested most of the 
counties between the Missouri and James rivers south of the 
Huron, Pierre and Deadwood Division of the Chicago & North¬ 
western Railway. The strong winds during the winter of 1887-88, 
followed by the dry summer of 1888, and possibly a fresh importa¬ 
tion of seed into the flax fields of Faulk or McPherson Counties, 
caused the weed to spread, within two years, to nearly all the 
remaining counties between the Missouri and James rivers in South 
Dakota, and to infest the southern tier of counties in North Dakota. 
At about the same time it invaded nortliern Iowa and northeastern 
Nebraska.” 
No definite date can be assigned for the introduction of tlie 
Russian tliistle into Colorado. We have authentic information of 
its existence here in 1892, but it was undoubtedly introduced earlim*, 
and possibly several years earlier. It has attracted no notice and 
received no attention until within the present year. During the 
last tliree months a large number of inquiries have been received 
by this department, most of them accompanied by specimens of 
the ])lant. 
From the remoteness of the localities reporting the plant, it is 
a])parent that it has not sj)read from one i)oint of infection, and the 
manner of its introduction is a matter of speculation. It is said to 
have been introduced into Morgan C'ountv bv a colonv of Russians, 
who brought it as an impurity in seed. At Denver, LaSalle, and 
Longmont, plants were first discovered upon railroad property, and 
the development and distribution i)oint to the railroad lines as 
points of infection, and to })assing trains as the means of introduc¬ 
tion. 
