312 POTAMOGETON PENSYLVANICUS. [Szss, LXXII. 
paper in the “ Medical Repository” of 1808 and 1811, and 
the “ Critical Review” of 1817, led me to try and trace out 
its real name. There was no doubt Wolfgang’s pumilus was 
the plant, as Dr. Lange sent me an original specimen from 
Bernhardi, and pensylvanicus and Claytonii were certainly 
the same. Then Dr. Morong (/.c.) adopted the name P. 
Nuttalii, which occurs in the same volume of “ Linnea,” but 
on the page before pensylvanicus. He has been followed by 
Dr. Griibner in Engler’s “ Das Pflanzenreich,” Heft 31, 1907. 
Dr. Morong seems not to have noticed Tuckerman’s remarks 
on the figure of the fruit of Muétalii in the “ Linnea.” The 
result of this naming is that pensylvanicus is certain, that . 
Nuttalii is not, as we have no specimens, so far as known, in 
any European herbarium. But there is Rafinesque’s name 
of P. epihydrum, “ Med, Rep.,” 2nd Hex. v. 354, 1808. He 
there says his plant is the same as Michaux’s natans var. 
6, of his 1803 Flora.!. In the Vienna Herbarium there is a 
specimen named “ P. natans, Michaux. In fluy. Virginia. 
Beyruth.” This is P. Claytonii. This of course makes it 
likely that Rafinesque’s name may have to be accepted, but 
no specimens so named by him are known. A specimen from 
him (no date) in the Delessert Herbarium at Geneva named 
“ P. fluitans Auct. Am.” is Claytonui. It is the only specimen - 
of Rafinesque’s that I have seen. And the earlier American 
botanists (Pursh, Bartram, etc.), named it P. flatans. 
In North America it occurs in the British Possessions in 
Vancouver's Island, British Columbia, Upper and Lower 
Canada, New Brunswick, Nova Scotia, and Sable Island. 
In the United States, Maine (Fernald !), south to Georgia 
(Glasgow Herb.!), New England! to Oregon !, Washington 
Territory ! and California!; in Jamaica! and Porto Rico}. 
It is probable it has been introduced with cotton in some 
way; it occurs in the States where this is grown—ze. Virginia }, 
Carolina !, Georgia !, Tennessee !, Louisiana !, etc. 
I have asked the author of the “Flora of Halifax,” 
Mr. Crump, to investigate the spot next summer, and*make a 
complete list of the plants with which it is associated. Miss 
Vigurs names the following as having been observed by her: 
Potamogeton crispus, Linn., Elodea, a Ceratophyllum. Glyceria 
aquatica and Alisma Plantago were growing with or near it. 
1 “F], Boreali Americana,” 2 vols., 1803. 
