TETRANDRIA TETRAGYNIA. PotamOgeton, 



121 



In ponds and rivers on sandy soil : New Jersey to Caro- 

 lina, 1/. July, Aug. v.v. Leaves larger than any of 

 the other sorts 3 spike greenish brown. 



P, foliis alternis opposltisve lanceolato-ellipticis undulatis crispum. 



serratis spicis paucifloris. — IVilld. sp. pi. 1. p. 714. 



Icon. Fl. dan. 927. Curt. lond. 5. t. 15, 



In rivers and ponds : Canada to Virginia. 1/ . June, 



July. v.v. Spikes greenish red, small. 

 , P. foliosum ; folii's sessilibns angusto-linearibus planis, paudjiorum. 

 spicis capitatim subquadrifloris. 



P. gramineum, Mich.fi. amer. I. p. 102. 



In rivers near the sea-coast of Lower Carolina, 11 . 

 . P. foliis praelongo-setaceis approximatis distichis basi va- pecdnatum. 

 ginantibus, spicis terminalibus interruptis verticillatis, 

 fructibus ovatis turgidis. — Smith fi. hrit. 1. p. I'^J . 



P. marinum. Mich'fl. amer. I. p. 102. 



In ponds and slow-flowing waters : Canada to Pensylva- 

 nia. 1/ . July. v. v. Only the spikes appear above 

 water ; flowers seldom. 



155. rvUPPL\. Gen.pL235. 



1. Ruppia. TFilld. sp. pi. I. p. 7 17. 



Icon. Engl. lot. \36. Mich. gen. 35. Fl. dan. 364. 

 On the mouth of most rivers in North America. IJ.. v.v. 



maritima. 



