BOTANY OF CROP PLANTS 



PART I 



CHAPTER I 

 THE SEED PLANT BODY 



The seed plant body, like the human body, is made up of 

 a number of separate parts or members. In the lowest plant 

 group, the Thallophytes (thallus plants), including algae 

 (pond scums, sea weeds, etc.), and fungi (molds, mildews, 

 mushrooms, etc.), the plant body is relatively simple; it is 

 not composed of distinct members, such as leaves, stems, 

 roots and flowers. Such a simple, undifferentiated plant 

 body is called a thallus. Between the typical thallus of algae 

 and fungi on the one hand, and the highly complex and well- 

 differentiated body of seed plants on the other, there are 

 many intermediate forms, as for example, among the liver- 

 worts (Hepaticae). 



Principal Parts of Seed Plant Body. — The parts of the 

 plant body may be classified according to the work they do, 

 into two groups: (i) those that carry on vegetative activity; 

 and (2) those that carry on reproductive activity. In seed 

 plants, the stems, leaves and roots are chiefly concerned with 

 maintaining the life of the individual plant, that is, carrying 

 on the vegetative (nutritive) functions, such as absorption of 

 materials from the soil, manufacture of foods, respiration, 



