NUTRITION AND SEASONAL LIFE OF PLANTS 131 



habit of the white sweet clover. In such a plant the first season 

 is devoted largely to the manufacture and storage of food, and 

 this process takes place for the most part in the more or less 

 fleshy taproot. The processes concerned with the migration of 

 food into this taproot and its storage in specialized storage tissues 

 are identical with those already described for the bean. The special 

 storage portions of the root are found in tho very broad wood rays 

 and cortex, which become gradually filled with starch and protein 



Second 



(Photosynthesis 

 and reproduction) 



FIG. 05. The seasonal history of the biennial white sweet clover (Melilotus) 



during the late summer and autumn, after the plant has reached 

 its growth for the season. During this period also the buds are 

 laid down on the upper broad crown of the main taproot for 

 the early growth of stems and leaves in the spring of the second 

 season. These buds and the taproot then pass the winter in the 

 condition shown in Fig. 65. The following spring, when these 

 buds start to grow, wood-ray cells convert their reserve food by 

 digestion into soluble sugar and protein, which move at first 

 horizontally along the rays, then upward in the phloem into the 

 expanding buds. In these buds the concentration of soluble 

 foods in the cells is kept low by its constant conversion into 

 new cellulose walls and new protoplasm for the cells and tissues 

 formed in the growing leaves and internodes. The food streams 



