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HOW DO SEED PLANTS SUCCEED IN LIFE? 



store food which help the plant to get a better start in the spring ; 

 the ability to stand excessive heat and cold; and the ability to 

 maintain themselves in wet or dry conditions. They often grow 

 luxuriously under conditions that would kill an ordinary plant 

 and grow so rapidly that they choke out their less favored com- 

 petitors. Particularly, their seeds have great vitality, and may 



stay alive in the soil 

 as long as twenty- 

 five years after dis- 

 persal from the 

 parent plant. 



Practical Exercise 1. 



Find a number of dif- 

 ferent ways in which 

 weeds in your locality 

 show vitality. 



Weeds have good 

 methods of self- 

 protection. Some 

 structures by which 

 weeds protect them- 

 selves have already 

 been noted, such as 

 the hairs of the 

 mullein or the prickly 

 stem and the leaf of 

 the thistle. Many 

 grow low to the 

 ground, as the dan- 

 delion. Some are 

 distasteful to ani- 

 mals and others have a disagreeable odor, as the wild onion, tansy, 

 or yarrow. Most weeds have the ability to resist disease and 

 some, such as the dodder, are parasites and get their living from 

 host plants, giving nothing in return. 



Individual Project. Collect and bring to class twenty-five common 

 weeds. Mount them in passe-partout frames under glass. The col- 

 lection will be of much value in weed identification. 



Department of Agriculture 



The field daisies are able to grow in poor soil and they are 

 thus able to smother the useful plants. 



