SPERMATOPHYTA ANGIOSPERMS HELOBIAE 333 



Fig. 131. Pond-weed (Potamogeton natans). 1. 

 Apex of flowering shoot. 2. Flower viewed from 

 above. 3. Flower viewed from side. 4. Diagram 

 of flower. (After Wossidlo). 



Fiar. 132. Pond weed (Potamogeton). Common in fresh water 

 po nds . 



