Fig. 32: Potamogeton filiformis: a, apical part of plant, showing the fleshy linear 

 leaves with adnate stipules sheathing the young leaf blades and the 5 regularly spaced 

 flower whorls, X 2; b, habit, X %; c-f, leaf tips, showing variation from blunt to sub- 

 mucronate, X 4; g, sepaloid connective, showing pronounced veins, X 8; h, flower, 

 X 8; i, achene, showing rounded back and nearly central, wartlike beak, X 8; j, achene 

 (longitudinal section), X 8. (From Mason, Fig. 13). 



