aiEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 1 7 



Yellowstone Park : Shoshone Geyser Basin, Clifford Richai'L- 

 son (ace. to Morong) ; Sour Creek, 1885, Tzuccdw ^12. 



Potamogeton pectinatus L. Sp. PI. 127 [Man. R. M. 364; Morong, 



Mon. 51 ; 111. Fl. I : 77 ; Bot. Cal. 2 : 19S]. 



In ponds and shallow lakes up to an altitude of 1000 m. 



Montana: Great Falls, 1885, A'. .S'. Williams, 284: Missoula, 

 1880, Watsoji. 



Potamogeton Robbinsii Oakes, Hovev's Mag. 7 : 180 [Man. R. M. 



364; ]Morong, Mon. 54; 111. Fl. i: 78; Bot. Cal. 2: 198]. 



It is reported by Coulter as growing in the Yellowstone Park, but 

 I have seen no specimens from there. 



Potamogeton perfoliatus L. Sp. PI. 126 [Man. R. ]M. "^^6-;:^ : Morong, 

 Mon. 2.^'^ Ill- Fl- 1:71: Bot. Cal. 2: 197]. 

 In lakes, ponds and slow streams up to an altitude of 1000 m. 

 Montana: Missoula, 1880, IWi/sou. 



Potamogeton perfoliatus Richardsonii Bennett, Britten's Journ. Bot. 

 27: 25 [Morong, Mon. 33; 111. Fl. i : 71] ; Potanioo-cton perfoli- 

 atus lanccolatns Robbins, in Gra}', Man. Ed. 5, 448 [Man. R. M. 

 363 ; Bot. Cal. 2 : 197] : not Blytt. 

 More common than the species and reaching a higher altitude, 



viz., 2200 m. 



Montana: Mystic Lake, 1897, //. S. Jcnniiigs. 

 Yellowstone Park : Lake, 1885, Tzcccdv, ^ij. 



* Potamogeton Zizii Roth, Enum. i : 531 [III. Fl. i : 70] ; Potamo- 



orlo)i aii^itsli/'oliiis Berch. & Presl, Rost. 19 [Morong, Mon. 29] ; 



not DC. 



This is characterized by its sessile submerged leaves. It grows in 

 lakes and streams at altitudes from 1000 to 2500 m. 



Montana : Haydcn Siirvex, ace. to Morong. 



Yellowstone Park: Shoshone Lake, Aug. 10, 1897, Rydberg 

 & Pcsscy, J/24. 



Zannichellia palustris L. Sp. PI. 969 [Man. R. M. 362 ; Morong, 



Mon. 57; 111. Fl. i: 80; Bot. Cal. 2: 193]. 



In pools and the shallow margins of ponds and lakes, up to an alti- 

 tude of 1000 m. 



Montana: Sand Coulee, 1891, R. S. Williams , jjj ; Madison 

 River, 1886, Tzvccdy, logg. 



