Fig. 39: Potamogeton diversifolius: a and b, achenes, showing the angular often 

 denticulate outline of the dorsal keel and the strongly coiled embryo, X 16; c, upper 

 part of stem, the floating leaves elliptic, the submersed leaves linear, X 2; d, habit, 

 showing the numerous capitate subsessile spikes, X %, e and f, tips of submersed leaves, 

 X 10; g, linear leaf blade arising from stipule, and the long free ligule, X 4; h, mature 

 capitate spikes, showing reflexed peduncles in axils of submersed leaves, X 2; i, flowers 

 in spike, X 8. (From Mason, Fig. 17). 



