Fig. 41: Potamogeton amplifolius: a, upper part of stem, showing floating leaves, 

 the stout upwardly thickened peduncle and acute stipules, X -/-,; b, habit, showing 

 rhizome, arcuate submersed leaves, broad stipules and densely whorled flowers, X %; 

 c, sepaloid connective, X 6; d, achene (longitudinal section), X 6; e, achene, showing 

 the flat sides and prominent beak, X 6; f, single tlower, X 6 (From Mason, Fig. 27). 



