120 



TETRAKDRIA TETRAGYNIA. 



154. POTAMOGETON. Gen. pi. 234. 



natans? 1,P. foliis longe petiolatis natantibus sublanceolato-ovali- 



bus, primariis nonnullis subcordatis. Mich.fi.amer. 1. 

 p. 101. 

 In ponds and slow-flowing waters, common. 1/ . June, 

 July. V. V. Floating in the water ; flowers, as all 

 the following, in spikes axillary or sometimes ter- 

 minal, small and of a greenish colour. It is doubtful 

 whether this is not a new species, but I had no oppor- 

 tunity to compare it in a living or dried slate with the 

 European plant. 



2. P. foliis inferioribus longissimis linearibus, superioribus 

 lanceolatis nervosis coriaceis, omnibus petiolatis. — 

 JVilld.sp.pl. I. p. 713. 



P. foliis lanceolato-oblongis, petiolis longis. Gron.fl. 



virg. 339. 

 In ponds on the barrens of New Jersey and Carolina. 



% . July. V. V. 



3. P. foliis superioribus petiolatis ellipticisutrinque attenua- 

 tis, inferioribus coniertis sessilibus linearibus. Willd. 

 sp.pl. l./j. 713. 



P. hybridum. M'tch.Ji. amer. I. p. 101. 

 In slow flowing waters of Virginia and Carolina. 1/ . 

 June. V. V. 



4. P. foliis superioribus oppositis lanceolatis quinquenervi- 

 bus brevi-peliolatis, inferioribus alternis flliformi- 



bus, spicis densis alternis folio brevioribus. — Willd. 



.sp.pl. 1. p. 716 ? 

 In small lakes and rivers, on the pine barrens of Jersey. 



)/. July, Aug. V. V. The upper leaves are scarcely 



half an inch long ; the whole plant very slender. 

 perfoliatum. 5. P. foliis cordato-ovatis amplexicaulibus omnibus im- 



mersis, spicis terminalibus, floribus alternis. — Mich. 



fi. amer. \.p. 101. IVilld sp. pi. 1. p. 713. 

 Icon. Fl. dan. IQd. Engl. hot. ^68. 

 In ponds and rivers, frequent : Canada to Pensylvania. 



1/. July, Aug. V. V, Spike of flowers only floating, 



brown. 

 lucens. ■ 6. P. foliis lanceolatis subsessilibus, costa media crassa, 



spicis longis cylindricis. Mich. Ji. amer. 1. p. 101, 



liquid, yp pi. l.p.714. 

 Icon. Fl. dan. ig5. Engl. lot. 370. 



Jluitans. 



heterophyl- 

 lum. 



seiaceum. 



