22 FLOBA OF PHILADELPHIA. 



With submerged leaves only. 



Without propagating buds and without glands. 



.Leaves with broad blades, mostly, lanceolate or ovate, many- 

 ■' nerved. 8. P. perfoliatus. 



Leaves with narrow blades, linear or oblong-linear, several- 

 nerved. 12. P. foliosus. 

 Leaves with narrow blades, capillary or setaceous, 1-ne'rved or 

 nerveless. 9. P. confefvoides. 

 With propagating buds or glands, or both. 

 With buds, but without glands. 



Leaves serrulate, 3-7-nerved. 10. P. crispus. 



Leaves entire, with 3 principal and many fi-ae nerves. 



J.1. P. zosteraefolius. 

 With both buds and glands. 



Glands large and .translucent, buds rare. 



'•'•'" '"' . ".{ ."'. 13. P. obtusifolius. 



Glands small, often dull ; buds common. 



14. F. pusillus. 

 Stipules adnate to the leaves or petioles. 



With both floating and submerged leaves. 



Submerged peduncles as long as the spikes, claVate, often recurved. 



15. P. dvoersifoUus. 

 Submerged spikes sessile or nearly so. 16. P. Spirillus. 



With submerged leaves only. 



Drupelets without keels or obscurely keeled. 17. P. pectinatus. 

 Drupelets strongly 3-keeled. _ 18. P. Bobbinsii. 



^ 1. Potamogeton natans K M. p. 42. Ponds and streams. Summer. 



2. Potamogeton Oakesianus Bobbins. M. p. 42. Still water. Summer. 



Burlington— 'Brown Mills (C). Atlantic— Bstelville (C), Mill Pond 

 10 miles west of Atlantic City (He.). Ocean— Forked River (Le.). 



3. Potamogeton amplieqliu.s Tuckerm. M, p. 43. Ponds and rivers. 



Summer. 



Philadelphia — Schuylkill above Philadelphia (Cr.). Bucks — Hoot's 

 Dam (Fr.). Delaware— Rifle Eange (Cr.). Lehigh — Lehigh Riv,er (Kr.). 

 Northampton — (P.) . 



Camden — In the Delaware (C). Gloucester— Big Timber Creek (He.). 



4. Potamogeton pulcher Tuckerm. :M. p. 43. Ponds. Summer. 



Bucks— Bristol (Cr.). Lehigh^ (P.). Northampton— (P.). 



Gloucester — Repaupo (Li.) (Wn.). Salem— Elmer (C). Cape May — 

 Wildwood (C.). Atlantic— Atlantic City '(C). Ocean— -Toms River (C). 



New Castle— Col. Andrews, Tatnaill; Newport, Commons; Shelpot 

 Creek, Cedar Swamp, Commons. 



5. Potamogeton Ntj:TTALLIi Cham. & Sch. M. p. 43. Ponds and streams. 



Summer. 



■6. Potamogeton lonchites Tuckerm. M. p. 43. Ponds and slow streams. 

 Late summer. 

 Philadelphia^- Angora,' C. A. Boice (Te.). Delaware— Tinicum (B. 

 Sm.). Lancaster— Opposite Marietta (Le.), Safe Harbor (P.). North- 

 omjrtow-r-Easton (P.). 



(Bovcester—Miekleton (He.), Swedesbbro (Li.). 

 New Castle— Cherry Island, Commons. 

 1. Potamogeton beterophy^MJS Sehreb. M. p. 44. Still or flowing water. 

 Summer. 



