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 Pleu- 

 rococcus, the yeasts, and bacteria already studied. But there are others 

 also, which, though commonly seen, must remain unknown unless ob- 

 served 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 vari- 

 ous 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 : 



Root (with or without branches) 



Stem (with or without branches) 



Plant Body " 



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. 



