17 



Figure 7 

 Elodea nuttallii: A. habit, x '/2. B. leaf, x 2 '/a. C. pistil- 

 late flo^ver, x 5. D. staminate flower, x 5. E. stami- 

 nate bud with spathe, x 5. 



Elodea canadensis: F. habit, x '/2. G. staminate flower 

 with spathe, x 5. H. pistillate flower, x 5. 1, leaf, x 2Vi. 



