203 A LESSON ON BUTTERCUPS. 



(fc) Along the stem of necessity there passes the crude 

 sap absorbed by the roots from the soil. This passes to 

 the leaves, returning along the stem again as elaborated 

 sap (food) to the whole plant. 



(c) Sometimes the stem of a plant is used in a more or 

 less specialised form to store reserves of food stuff, e.g. as 

 tubers and conns. 



(d) Also in some cases for the multiplication of the 

 plants as runners, either above or below the ground, e.g. the 

 creeping buttercup (E. repens). 



The Leaf. 



As already mentioned the leaf 



(a) decomposes carbon dioxide in sunlight ; 



(6) elaborates food, building up organic substances 

 starch, sugar. 



(c) transpires excess of moisture from the plant. 



The Flower. 



The production of seed is the primary function of the 

 flower. 



The Seed. 



The function of the seed is the continuation of the 

 species. 



Summarising at this point we may say that the life of a 

 plant such as our buttercup is manifested in its reacting 

 (in a characteristic manner) to 



Moisture, 

 Minerals, 

 Oxygen, 

 Carbon dioxide, 

 Sunlight. 



