36 LIVING PLANTS 



present time it is especially abundant in this 

 part of the country, not only in cities and 

 towns, but on farm lands and along high- 

 ways. 



The inference appears well founded that the 

 plant has found its most congenial domain 

 between the Alleghany and Rocky mountains, 

 and between the fortieth and forty-third par- 

 allels. The region in which it has become so 

 well established and so abundant as to take 

 on the character of a prominent weed em- 

 braces the northern half of the states of Ohio, 

 Indiana, Illinois, the southern parts of Mich- 

 igan and Wisconsin, and part of Iowa. Out- 

 side of this region it occurs locally in every 

 direction so that its distribution may now be 

 said in general to extend throughout the 

 United States. 



Probably no one thing about this plant im- 

 presses the observer more that the appear- 

 ance of having "come to stay," an expression 

 used by many of those who have recorded 

 their first acquaintance with it. It is a weed 

 not only because it is a ''plant out of place," 

 but because it possesses certain attributes 

 that enable it to maintain itself wherever a 

 seed finds moisture and soil enough for the 

 forthcoming plantlet to gain a foothold. 



Before discussing this pre-eminent trait of 

 the plant, however, it will be well to mention 



