A TEXT-BOOK OF GRASSES 



CHAPTER I 

 INTRODUCTION 



ECONOMIC botany is that branch of the science of 

 botany which treats of the uses of plants. All animals, man 

 included, are dependent directly or indirectly upon plants 

 for their existence. With the exception of water and a 

 small amount of mineral matter such as salt, the food- 

 supply of all animal life finally may be traced back to 

 the constructive metabolism of plants, a process depend- 

 ent upon photosynthesis. Many animals derive a whole 

 or a part of their food from other animals, but sooner or 

 later in the chain of relations between animals and their 

 food-supply a point is reached where the ultimate deriva- 

 tion is from plants. The vegetable kingdom provides 

 directly a large part of the food for man and for his 

 domestic animals. It provides the fibers from which much 

 of his clothing is made; much of the material for construct- 

 ing his home and the articles with which it is furnished; 

 many of the drugs, medicines, dyes, condiments, bever- 

 ages, and a great variety of other useful articles or 

 substances. 



Of the natural families of plants that contribute their 

 quota to supply the wants of man, the grass family exceeds r 

 all others in the amount and value of its products. To 

 A (l) 



