FLUVIALES veint. (Potamogeton.) 131 



flaccida; caulis elongatus. Koch. P. heterophyllus y 

 elongatus Meri. et Germ. Germ. 1. 845. P. gramineum 



Linn. Suec. 2. n. 151. (Jide Fries.) P. gramineus a flu- 



vialis et /? lacustris Fries. I. c. 

 /5) heterophyllus Fries. I. c. Koch. I. c. ; folia submersa bre- 



viora, recurvata, plerumque rigidiora, non raro rigida. 



Koch. P. heterophyllus a foliosus Meit. et Koch. I. c. 



P. Proteus C. heterophyllus Cham. in Linnaea 2. 202. 



P. hybridum Pretagna, Inst. hot. 2. 289? Thuill. Paris. 



P. augustanum Balbis. Misc. 14. t. 3. P. distachvum 



Bellardi. P. crassipes Kit. P. gramineum Flor. Dan. 



t. 222. Roth. Germ. 1. 74. (fide Cham.) P. lanceolatum 



Poir. Encycl. suppl. 4. 536? P. lanciformis Roem. et 



Schult. Syst. 3. 512? 

 y) Zizii Koch. I. c. ; duplo triplove antecedente major; folia 



praecipue superiora obtusa, at semper mucrone praedita, 



et saepe evidenter undulata. Koch. P. heterophyllus 



d latifolius Mert. et Koch. I. c. P. Proteus B Zizii Cham. 



I. c. 201. *) P. lucens d coriaeeus Mert. et Koch. Germ. 



1. 850. P. lucens /5 heterophyllus et y amphibius Fries. 



I c. 34. 

 — In aquis fluentibus et stagnantibus Europae et Americae bo- 

 realis. — Chamisso (1. c. p. 196.) fructus P. Protei sui descri- 

 bit ut sequitur: nux lentiformis, oblique obovatd ; stylo faciali; 

 dorso latiore, tricarinato; carina mediaacuta; lateralibus obsole- 

 tis; lateribus planiusculis, in faciem cuneatis; putamen cras- 

 siusculum, lignosum. nec durum. — Sprengel (Syst. 1. 498.) 

 P. setaceum Pursh. cum P. heterophyllo Schreb. conjungit. 



6. P. MTENS Weber. Flor. Hols. suppl. n. 11. secundum 

 Nolt. Nov. Flor. Hols. 18. Fries. Novit. ed. 2. 34. Reichenb. 

 Germ. 8 et 138. **) Koch. Synops. 675. Foliis submersis mem- 

 branaceis, pellucidis, lanceolatis vel lineari- lanceolatis, acutis, 

 muticis, basi rotundatis, semiamplexicaulibus, margine scabrius- 

 culis; natantibus oblongis lanceolatisve, in petiolum attenuatis, 

 coriaceis ; his saepe deficientibus ; pedunculis apicem versus 

 plerumque crassioribus ; fructibus exsiccatis compressis, mar- 

 gine carinatis; caule ramosissimo. Koch. P. curvifolius Hartm.***) 

 Scand. ed. 2. 45. Mert. et Koch. Germ. 1. 846. 



a) salicifolius Fries. I. c. 34. Koch. I. c. ; folia submersa li- 



neari-lanceolata, stricta; caulis elongatus. Koch. P. gra- 



mineum Wahlenb. Vps. 57. 



e ) Chamisso huc ducit P. Iucentem Engl. Bot. t. 376 



) Reichenbach huc ducit P. gramineum R 

 im Rolh. Enmn. 



*) In fluvio Diina Rossorum legit Eichwald 



* e ) Reichenbach huc ducit P. gramineum Roth. Flor. et P. hetero- 

 phyllum Rolh. Enmn. 



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