49 



Plaxts and Majst : Weeds and Diseases. 



By Kobert Hessleb. 



Indiana maj^ be divided topograpliically into three parts — the soutliern 

 liilly, ttie central rolling, and the northern part flat and wet. With the 

 exception of the northwest, the whole State was originally densely covered 

 with forests. The wet lands are being drained more and more and the land 

 brought under cultivation. The soil is rich and produces heavy crops. It is 

 surprising to learn that along the Kankakee first year crops require prac- 

 tically no cultivation, because there are no weeds. The next year a few 

 come in ; many are found by the third year, and after that farming becomes 

 mainly a contest against weeds. 



Bringing the land, whether densely forested or marshy prairie, into 

 cultivation means displacing the native flora by foreign plants. These 

 latter are of two kinds — those brought in purposely, cultivated plants of all 

 kinds, and those brought in unintentionally, mainly weeds. Today most of 

 our worst weeds are foreigners that have come from all parts of the world, 

 especially from Europe, where for ages weeds have been fought and where 

 certain ones have developed resisting qualities. Weeds are introduced in 

 imported seed and also largely in hay and straw, used in crating. In waste 

 places about cities where trash is thrown one may expect to find "new 

 weeds." Some are also brought in by the railroads, the seed lodging on 

 9ars and falling off. Some are brought down by rivers. 



When man cuts down the forests, plows the prairies and drains the 

 marshes, he is disturbing the "balance of nature," and animals and plants 

 move about to find new, suitable homes. Animals, of course, move about 

 very freely ; if their homes are destroyed they seek new ones ; every botanist 

 knows that plants do the same. That is, seed is carried about and germi- 

 nates here and there; if conditions are favorable the plant may thrive, 

 become re-established. If conditions are unfavorable it may perish very 

 quickly, or it may persist for a year or two. Thus at present some of our 

 native plants may be seen in localities where they had not been seen tlio 

 year before or where they had not been seen for many years. I have a 

 number of notes of such "moving about" plants. 



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