— 280 — 



The results of these examinations might be summed up brietly 

 as follows: 



F. fiu'dans aiict. consists of two quite different plants viz., an 

 independent species belonging to the P. jjolijgonifolius-gvoup, and 

 a plant of hybrid origin viz. F. lucens x liatans. As we ought 

 not to increase the number of names more than absolutely neces- 

 sary, the name of P. fluitans should be kept for the one form, 

 namely the Neckar-plant, partly because the bastard as a bastard 

 cannot claim an independent name that is due to the independent 

 species — and partly because the hitlierto known original specimens 

 of Roth's P. -finitans all belong to the Neckar-plant, which 

 for the future ought only to bear the name of P. ftuitans Roth. 



