TETRANDRIA TETRAGYNI A » Potamogeton. 
In ponds and rivers on sandy soil : New Jersey to Caro- 
lina. V. . July, Aug. v. v. Leaves larger than any of 
the other sorts $ spike greenish brown. 
7. P foliis alternis oppositisve lanceolato-ellipticis undulatis 
serratis, spicis paucifloris. — Willd . sp. pi. 1. p. 714. 
Icon. FI. dan. 927. Curt. lond. 5. t. 15. 
In rivers and ponds: Canada to Virginia. 1/. June, 
July. v.v. Spikes greenish red, small. 
8. P. foliosum j foliis sessilibus angusto-linearibus planis, 
spicis capitatim subquadrifloris. 
P. gramineum. Mich.fl. amer. l.p. 102. 
In rivers near the sea- coast of Lower Carolina. 1/ . 
P. foliis praelongo- setaceis approximatis distichis basi va- 
ginantibus, spicis terminalibus interruptis verticillatis, 
fructibus ovatis turgidis.— —Smith fl. hrit. 1. p. 197. 
P. marinum. Mich.fl. amer. l.p. 102. 
In ponds and slow-flowing waters : Canada to Pensylva- 
nia. I/ . July. v. v. Only the spikes appear above 
water 5 flowers seldom. 
155. RUPPIA. Geji.pl. 235. 
1. Ruppia. Willd. sp. pi. 1. p. 717. 
Icon. Engl. lot. 136. Mich. gen. 35. FI. dan. 364. 
On the mouth of most rivers in North America. 1/ . v. v. 
121 
crispum . 
pauciflorum . 
pectinatum . 
maritima. 
