MIGRATION OF WEEDS 85 



whence it was spread to all the lower streams of the St. 

 John. 



Squirrel-tail grass was common about the great lakes, 

 where it was indigenous, but was not common in many 

 parts of Wisconsin in 1883, although, even then, it was 

 frequently seen in low grounds about Madison, and is 

 now abundant. It was in parts of Iowa in 1865, and now 

 occurs in every county of the state. 



The hawkweed, according to Dr. Jones of Vermont, 

 became a weedy plant between 1860 and 1875. Mr. W. 

 H. L. Truman of Brockport, N. Y., referred to it as spread- 

 ing from cultivation. It was introduced as a cultivated 

 plant in 1818. It was recorded in Vermont in 1873, and, 

 at about the same time, in Rhode Island. 



With these annuals, it is only essential that they ma- 

 ture their seed, but with perennials they must not only 

 mature their seed, but the plants must be able to survive 

 the winter. Those who hold that perennials cannot be 

 acclimated will find an exception in Solatium carolinense, 

 Darlington, in his "Flora Cestrica," makes the statement 

 that it was introduced by the late Humphrey Marshall 

 into his botanical garden at Marshalltown. Beck, in 

 1833, gave its distribution as Pennsylvania to Carolina, 

 west to Mississippi. In the second edition of Gray's 

 "Manual," Connecticut is included ; it is also included in 

 the fifth edition ; and in the "Synoptical Flora" it is said 

 to occur from Connecticut to Illinois and southward. Dr. 

 Eaton, however, writes me that he has not seen it, and 

 there is no record of its occurrence in that state, except 

 the specimens found by Dr. Robbins. That the weed is 

 still spreading in West Virginia is indicated by Mills- 

 paugh. In 1852, Brendel found it native in Peoria, Illi- 

 nois. Solanum carolinense also occurs in Wisconsin. 



In recent years, many weeds have been introduced by 

 means of impure seeds. Throughout the state of Iowa, 

 one will find that our clover meadows contain carrot, 



