(7) — 99 — 



= P. Claytonii Tuck. ! in Sïll. Jour. ser. 1, XIY, 38, 1843 = 

 P. fiuitans Pursh FI. Am. Sept. 1, 120, 1814 = IF. epihydrum 

 Rafin. Med. Bep. 2 Hesc. 5. 354, 1808 = P. Nidtallii Cham. 

 Linn. 1. c. teste Morong. 



« P. fiuitans (Rafinesque) Arkansas, Etats-Unis. » This is the 

 first spécimen of a Potamogeton, I hâve seen from Rafinesque in 

 any herbariuin. There is great difficulty in deciding what some 

 of Rafinesque's naines mean in his descriptions of N. American 

 Potamogetons. About 1840-48 this plant was named by some 

 American botanists (i. e. Rugel) P. fiuitans; by others P. lietero- 

 pliyllus (i. e. D r G. Watson). 



It is not decided which name the species should bear, whether 

 epihydrum, pensylvanicus, or Niitallii. D r Morong in his N. Amer. 

 Naiadacese refers it to the last on the strength of Chainisso's figure 

 of the fruit. To me that figure as well accords with P. Oakesianus 

 Robbins., another N. American species, but unfortunately I hâve 

 never been able to trace Chamisso's spécimen of his Nidtallii. 

 The species is a well defined one occuring in Canada from Québec! 

 to Vancouver's Island!, and in the United States from Maine ! to 

 Georgia!, and Masschusets ! to Oregon ! 



9. P. hybridus Michx FI. Bor. Amer. 1, 101, 1803 

 = P. diversifolius Rafinesque Med. Eep. 2 nd Hex. V, 354, 

 1808 = P. capïllaceum Poir. En. Meth. supp.'TV, 535, 1816. — 

 Old spécimen for Carolina. USA. 



D r Morong rejects Michaux's name because Thuillier used it in 

 1790 (i. e. for P. heterophyllus Schreb.) as did Pentagna Inst. bot. 

 2, 289, 1787. 



There might be some valid reason for this if the name 

 had been used in America before; but no one confuses 

 Michaux's plant with Thnillier's, or Pentagna's. This name 

 changing causes Botany to be discredited with many. 



Gay made this into a new genus under the name of Spirillus 

 hybridus Gay Comp. Rend. Acad. 38, 702, 1854. 



In the Botan. Notiser 160, 1844 the name P.ZetterstedtiiWsi}].] 

 is referred to this species, but the description (in Bot. Zeit. 

 1, 256, 1843) better applies to P. dimorphwn Rafin. (P. spirillus 

 Tuck.) 



1 FI. Austral. VU, 171, 1878. 



