- 96 - (4) 



shows, though I hard forinerly so referred it. lu Flora Capensis 

 VIL 46 1897, I hâve referred P. Thunbergti Chain, to P. 

 americanus Chain, as a variety. Durand and Schinz (Consp. 

 FI. Afr. V, 494), naine it « P. nalans L. var. capensis Cham. », but 

 Chamisso nierely uses the capensis as a référence whence spéci- 

 mens corne, not as a variety. It is probable that inany of 

 Chainisso's naines really represent only endémie varieties of 

 P. americanus Cham., but in the then state of the knowledge 

 of the genus, there was no other course open; i. e. to give 

 them a naine and leave after students of the genus to place 

 them. The material even now at disposai is often poor, and in 

 1827 it vas inuch more so. 



4. P. americanus Cham. — « Potamogeton , n° 1820. 

 Linden coll.. 1844. Santiago de Cuba.» — a Potamogeton. Voyage 

 de Boivin 1846-52. » 



Spécimen with good fruit, which appears to be the same as the 

 Necker plant, which M. Raunkaier wishes to be accepted as 

 P. fliritans Roth. I do not agrée with him, and would refer to 

 M. Beeby's note on the subject 1 . It is again an attempt to naine 

 a little known plant as the type, and relegate a well known one to 

 another name. In every european herbarium the supposedhybrid 

 natans X lucens is accepted as Roth's type, and in the Munich 

 Herbarium are spécimens gathered by Schreber that Roth him- 

 self 2 says are his plant, this to me is convincing. 



In the Herbarium I hâve referred several spécimens to 

 Chamisso's P. americanus. Nolte in his herbarium! refers the 

 N. American P. lonchites Tuck. which he received from 

 Tuckerman hinself under the name of P. jlidtans as it was then 

 called is N. America. The question of how far ail thèse spécimens 

 are really referable to P. americanus, can only be answered 

 when a complète séries from ail parts of the world has been got 

 together. This I hâve been endeavouring to do, and if I ain 

 unable to study them, they will at least be available hereafter 

 to others. 



((Herbier de Mauritanie. — P. natans L. — Alger. Dans les 

 eaux stagnantes. N. Bové. Août 1837. » 



1 Journal of Botany 203, 1890. 



2 Roth in Catalecta Botanica, fas. J, 3J, 1796. 



