Fig. 35: Potamogeton joUosus: a, spike, showing short clavate peduncle, X 8; b, 

 achene, showing the thin undulate-toothed keel, X 10; c, habit, X %; d, fruiting spike, 

 showing connate and ruptured stipules, X 4; e, leaf tip, X 8. (From Mason, Fig. 23). 



