250 BULLETIN DE L'HERBIER BOISSIER. (2) 



« natans proper ». But if that is limiled to ail spécimens with large fruit 

 and the lamina at the base running down the pétiole fora short distance, 

 and forming a fold, or plicate base, we shall hâve that which is repre- 

 sented in the Linnean Herberium ilself. In two American species tins 

 plication also takes place (in P. amplifolius Tuck., and P. pulcher Tuck.) 

 but hère the submerged foliage at once seperates them. and in the majo- 

 rity of cases it may be seperated from the fluilans group by the stipule 

 which is geneally acute, and long. It will of course occur that there are 

 poor, and non fruiting spécimens that will hère to hère a mark of doubt 

 attached to them. It lias been said thèse are better destroyed but that 

 is not so, il will often occur that spécimens in one coll. will answer 

 queries in another. 



2. P. Oakesianus Robbins in Gray's Man. N. A. S. éd. 5, p. 485 

 (1867). 



In the Journal of Botany, p. 301 (1890), I referred this doubtfully to 

 P. Nuttallii Cham. Linnaea 2, 226, 1827. D r Morong in his Mon. N. Am. 

 Naid., p. 15, 1893 does not consider, I was juslilied in so doing, my good 

 friend is no more, and cannot answer me. I would only suggest the com- 

 parision of the figures Linnaea t. 6, f. 25, with D r Morong's t. 29, fr. 

 Unfortunately I hâve never been able to find Chamisso's spécimen of 

 N. Nutallii. 



3. P. amplifolius Tuckerman in Am. Jour. Se. and Arts. 2 d. ser. 

 VI, 225 (1848). 



The naine a very expressive one of the species. An endémie American 

 species to which I can add no extension of area to that given by D 1 ' Mo- 

 rong. 



4. P. pulcher Tuckerman in Am. Jour. Se. and Arts. l st ser. XIV, 

 38 (1843). 



But there is a much fuller description in séries 2, vol. 6, 224 (1848). 



Another endémie American species, with a more restricted range then 

 amplifolius, as it lias not been discovered in Canada, I hâve seen it 

 from Kentucky, and Missouri. 



5. P. lonchites Tuckerman in Am. Jour. Se. and Arts. 2 d. ser. VI, 

 226 (1848). 



In 1849 in the same publication Prof. Tuckerman, considered that his 

 plant was too near the European P. fluitans Roth, and so sunk his name. 

 In t lie 3 ed. of Eng. Bot. Syme considered lie had identified the Irish plant 

 (that liad been variously named) with Gay's spécimens atKew of Tucker- 

 man's lonchites. Following liim (and lie further supported his opinion by 



