CHAPTER XV 



THE PLANT-WORLD 

 SIMPLE PLANTS 



EVERYONE is already familiar with some of the higher groups of 

 plants known as "flowering plants," but everyone is. not familiar 

 with the fact that flowering plants are few in number, indeed, 

 when compared with the thousands of different kinds of minute plants 

 that cannot even be seen with the naked eye, and which do not bear 

 flowers. 



Prominent among these latter are such single celled plants as 

 Pleurococcus, the yeasts, and bacteria already studied. But there are 

 others also, which, though commonly seen, must remain unknown unless 

 observed under the microscope. 



To be able to discuss the plant-world intelligently one must know 

 certain terms commonly used, just as it was necessary to know the 

 various names of the many parts of the frog before the animal-world 

 could be intelligently discussed. 



The following outline and drawing (Fig. 92) will give such a knowl- 

 edge of terms : 



Plant Body < 



Root (with or without branches) 



Stem (with or without branches) 



Shoot 



Blade 



Leaves < 



Apex 



Margin 



Base of the Blade 



Veins 



Petiole (the leaf-stalk) 

 Leaf-base 



Stipules. (Small leaf-like structures 

 at the base of the petiole.) 



There are as many and varying classifications of plants as there are 

 of animals, but, four great groupings hold their own because these group- 

 ings are simple and easily understood. 



