Aquatic Seed Plants 



157 



families are best represented whose members live 

 chiefly on low grounds and in moist soil. A few rushes 

 (Juncaceae) invade the water on wave-washed shores 

 at fore front of the standing aquatics. A few sedges 



Fig. 67. Fruit clusters of four emergent aquatic seed 

 plants; arrow-arum {Peltandra), pickerel- weed {Pon- 

 tederia), burr-reed {Sparganium), and sweet flag 

 {Acorns). 



(Carices) overrun flood-plains or fringe the borders of 

 ditches. A very few grasses preempt the beds of 

 shallow and impermanent pools. A few aroids, such 

 as arrow arum and the calla adorn the boggy shores. 

 A few heaths, such as, Cassandra and Andromeda over- 

 spread the surface of upland sphagmun bogs with dense 



