PROPAGATION BY ROOTS 165 



Some trees, like the Black Locust and Silver-leaved Poplar, 

 are troublesome because of the readiness with which sprouts 

 spring up from the roots. Some of the weeds, such as Canada 

 Thistle and Field Sorrel, spread by developing new plants from 

 buds on their spreading roots. When the Dandelion is cut off 

 several inches under the ground, it often grows up again from 

 the portion of the root left in the ground. 



