"WEED MIGRATION 753 



consin (Pammel) ; Menominee Valley, 1888 (Runge) ; Kewaunee 

 county, 1889 ("Wheeler, Farwell) and in Seneca, New York. It is 

 abundant throughout the country and common in the northwest to 

 Washington. It is abundant in western Iowa and is rapidly 

 spreading eastward, also becoming an aggressive weed from Ames 

 north to the Minnesota line and westward. It was reported from 

 Europe (Denmark, Ostenfeld) 1895. 



Perennial Sow Thistle {Sonchus arvensis). 



This thistle was reported by John Torrey in 1826 in the northern 

 and middle states. Dr. Gray in 1848 in the first edition of the 

 manual reported it from Massachusetts, Staten Island, and in New 

 Jersey ; it did not occur in Pennsylvania, or at least was not men- 

 tioned by Darlington. The 5th edition' of Gray's manual, 1867, 

 gives its distribution "roadsides, etc.. New England, New York, 

 becoming more abundant;" the 7th edition (1908) says "from 

 Newfoundland to the Rocky mountains northward." Britton 

 (1901) places it in the same general region and west to Salt Lake, 

 Utah. The weed is not common in Iowa nor. in the surrounding 

 states except northward in Minnesota and Dakota. It was re- 

 ported from Grand Junction, Iowa, in 1898 by Tomson and from 

 Ogden, Iowa, about 1900; the writer found it in Englewood, Il- 

 linois, in 1886, and in northern Ohio in 1912. It has spread rapidly 

 in recent years in Canada, North Dakota and Minnesota, as 

 recorded in the agricultural press of the last two or three years. 



Galinsoga or Frenchweed {Galinsoga parviflora). 



Danger has given several accounts of the introduction of this 

 weed into Europe. The term Frenchweed seems to have been 

 commonly applied to this weed in Germany shortly after the French 

 soldiers occupied Hanover. One authority states that it was 

 brought from France with horse feed; it is said to have been in- 

 troduced into Germany about 1812. One authority states that the 

 weed was distributed from the Berlin Botanical Garden in the 

 year 1812, at any rate it was very common in Hanover in the year 

 1839 ; and has continued to spread. It may have spread from its 

 first introduction near Paris to other, places of France about the 

 year 1800, although there is no definite date as to when it made its 

 appearance in the vicinity of Paris. This plant is native to Peru 

 where it was discovered by Ruiz and Pavon about 1794, so 

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