LAWN BEAUTIFICATION 285 



The vitality and food provided by perennials 

 in most cases does not keep the plant alive more 

 than one season. The plant depends upon its 

 store of food being replenished by another 

 growth each season. If the leaves cannot develop 

 above the ground, so that raw mineral food col- 

 lected by the roots can be digested and stored 

 again underground, the plant cannot grow the 

 following season. 



Thus it is that by cutting off the plants con- 

 tinually for an entire season as soon as they 

 appear above ground they will die out and not 

 appear again on that area unless, of course, the 

 seeds are again introduced. 



Most weeds are provided with greater facilities 

 for reproduction and distribution than cultivated 

 plants. Most weeds also have some special means 

 for distributing their seeds over large areas. 



Many of them, such as cockleburs (XantJiium) , 

 sand burs (Cenchrus)^ burdock {Arctium) and 

 sticktights (Bidens), have burs surrounding each 

 seed which are made up usually of many hooks 

 or spines. These seeds attach themselves to the 

 clothing of persons and to the various domestic 

 animals, and are thus transferred from one lo- 

 cality to another. 



Many of the weed seeds such as thistles, wild 

 lettuce, dandelions, etc., are provided with a 



