SF nw A N k 
E ae 
SE RE ee E Oey gen ee E O 
1894.] Botany. 429 
cies are very widely distributed in Europe, Asia, North and South 
Africa, America and Australia. 
The Russian Thistle appears to have come to this country in flaxseed 
imported directly from Europe to South Dakota seventeen or eighteen 
years ago. For a while it was popularly supposed that the Russian 
settlers in South Dakota had purposely brought it for use as a forage 
plant, but this is now generally discredited. The name “Russian 
Thistle” is, however, so well fixed that it will continue to be used in 
spite of its inappropriateness, just as we say “Canada Thistle” for 
another Old World weed. 
For a number years after its introduction it attracted little attention, 
andit was not until seven or eight yearsago (1886) that it began to be 
troublesome in South Dakota. Since this time it has spread with 
much rapidity. Both of the Dakotas are now badly overrun with it. 
A few years ago it invaded Nebraska, coming into the State about Val- 
entine, and in Knox, Cedar and Dixon Counties. It probably came to 
the first named place with the United States soldiers stationed at Ft. 
Niobrara, a few miles east of the town of Valentine. The frequent trans- 
fers of troops from forts in South Dakota afford ready means of trans- 
portation to weeds of this nature. For several years it has been 
spreading from this point. The counties mentioned are separated from 
South Dakota by the Missouri River, but here and there are ferries 
over which teams frequently pass, and at these points the Russian 
Thistles are very abundant. 
The railroads have aided materially in their distribution, as is shown 
by the fact that by the end of 1893, Russian Thistles were to be found 
in nearly all parts of Nebraska, and in nearly all cases they were at 
first confined to a narrow belt along the track. Year by year they 
Spread from this belt, moving most rapidly along the lines of greatest 
travel. The wind, also, is an efficient agent in spreading them, since 
in many cases, the nearly spherical plants are broken off at the root, 
and rolled for long distances as “ tumbleweeds,” scattering their seeds 
throughout -their course. 
In Minnesota, Iowa and Wisconsin, Russian Thistles have appeared, 
and here again they have been brought in by the railroads. The rea- 
son why the railroads have had so much to do with the distribution of 
this weed, is that finding by the side of the tracks much unsodded 
ground, they spring up here in great numbers, and in the fall wien 
they break off by the winds they are caught up the passing trains rea 
carried away on the trucks or steps of the cars or on the pilot or in the 
machinery of the engine. 
