INGENUITY OF WEEDS 



the field before the harvest. One would think that those 

 exhausted the series, but far from it: the farmer cuts and 

 carries the crop, and for two or three days the ground is 

 almost bare, but if you revisit the field a week afterwards 

 you can no longer see the ground. The cut-off yellow stalks 

 of the corn are set off by a dark continuous green carpet of 

 flourishing weeds. This last, (5) the "waiting division" 

 of the weeds, remain quietly until the corn is removed and 

 then get through their flowering and seeding before the field 

 is ploughed up or covered by grass. 



Now if one thinks for a little over the cunning and 

 ingenuity of these proceedings, it is obvious that each single 

 weed has somehow learnt how to develop exactly at the right 

 time. Those especially which are intended (by themselves) 

 to form part of the seed mixtures must flower exactly at the 

 same time as the corn. As a matter of fact, most seed 

 mixtures are often full of weeds. In a single pound of 

 clover seed, no less than 14,400 foreign seeds, including those 

 of forty-four different weeds, have been discovered.^ 



Others scattered on the ground will probably be buried 

 and remain five to seven years below the surface, yet they 

 are ready to come up flourishing as soon as they get a chance. 



How has this been brought about ? It is only since about 

 1780 to 1820 that our present system of farming has 

 prevailed. In these 125 years, these weeds have found out 

 exactly how to establish themselves. 



The explanation is probably a very simple one. Every 

 weed which did not bloom and seed exactly at the right 

 time was killed and left no seed. This encouraged the 

 others, who have gradually brought about the neat little 



^ Report of the Botanical Department N.J. Agricultural Experiment 

 Station, 1891. 



276 



