34 METASPERMAE OF THE MINNESOTA VALLEY. 
Living species: 50+; fresh and rarely brackish wa- 
ters; cosmopolitan. Russia, 25; Europe, 38; N. America, 35 
(15 endemic); California, 19; Canada, 27; E. Sts., 29; Rocky 
Mts., 11; Pl. King., 10; Pl. Wheel., 4; S, Sts., 10. 
Fossil species: Tertiary; numerous forms described 
but all rather doubtful; 2 sp. clearer than the rest. Oeningen 
(A. Br.); S. France (Saporta). 
Potamogeton natans Linn. Spec. 126 (1753). 
Wats. and Coult, Gray’s Man. 6 ed. 558; Britt., Fl. N. J. 257; Webb., 
Fl. Neb. 97; Upham, Fl. Mion. 136; Chap., Fl. So. St. 446; Wats., Fl. Calif. 
II, 195; Mac., Fl. Can. II, 81; Coult., Fl. Colo. 362; Nym., Fl. Eur.; Led., 
Fl. Ross. IV, 23; Hook., Fi. Gt. Brit. 431; Richt., Pl. Eur. 11; Herd., F:. 
Eur. Russ. 124; Engl., Ascherson, Nat. Pflanz. II.1 207; Wats., King Exp 
337; Cov. Fl. Ark. 228; Hart, Fl. Scand. I, 431; Rothr., Alask. 445. 
Europe; Asia; Australia; Africa. 
North America: Anticosti, N. S., N. Br., Q., Ont., 
Owen Sound to Man. and Lake Athabasca; N. to Hudson Bay 
and Alaska; Vancouver; S. to Calif., Nev., Utah, N. Mex.; E. 
to N. Eng., N. J. and Fla. 
Minn. valley: Throughout; abundant; ponds, lakes 
and sluggish streams. 
HERB.: Ballard, 782, Swan Lake, Carver Co.; Ballard, 
587, Crystal Lake, Scott Co.; Ballard, 858, Page Lake, Carver 
Co.; Ballard 276, Jordan, Scott Co.; Ballard 321, Belle Plaine; 
Ballard 431, Prior’s Lake, Scott Co.; Sheldon 7238, Cottonwood 
river, near Sleepy -Eye; Ballard 900, Waconia; Taylor 1072, 
Douglas Co.; Sheldon 273, Duck Lake, Blue Earth Co.; Sheldon 
1088, Springfield; Kassube 223, Rocky Lake; Herrick 281, Min- 
netonka; Holzinger 265, Winona Co.; Bailey 391, Mud Lake; 
Sandberg 581, Chisago Co.; Herb. Sheld. 1693, Minneapolis. 
Potamogeton fluitans Roru. Fl. Germ. I, 72 (1788). 
P. natans var. fluitans CHAM. Adnot. 4 (1815). 
P. petiolavis Pr. Del. Pr. I, 151 (1822). 
P, natans var. angustatus M. and K. Rohl. Fl. D. I, 836 (1823). 
P. oblongus Mey. Chior. Hann. 519 (1836). 
?P. lonchites TUCKERM. Am. Jour. Sci. 2, VI, 226 (1848). 
Wats. and Coult., Gray’s Man. 6 ed. 560; Britt., Fl. N. J. 257; Upham, 
Fl. Minn. 136; Mac., Fl. Can. IT, 83, 369; Wats., Fl. Calif. IT, 196; Coult , Fl. 
Colo. 363; Chap., Fl. So. St. 446; Hook., Fl. Gt. Brit., 482°; Richt., Pl. Eur. 123 
Herd., Fl. Eur. Russ. 124; Engl., Ascherson, Nat. Pflanz. II, 1, 207; Wats., 
King Exp. 337; Hart., Fl. Scand. I, 431; Webb , Appx. Neb. 22. 
All Europe: cosmopolitan. 
North America: N. Br., Ont. to N. J.; W. to Minn., 
Iowa, Neb., Mex.; also Washington to Nevada. 
