POTAMOGETON BENNETTII. 3 



obhisifoUns,' so you are in good company. Put one of the leaves 

 under a 1 inch, and you will soon see what 1 mean. Margin and 

 venation are crispus" (Ar. Bennett in litt., 4.4.1891). 



Shortly afterwards these specimens were sent to me; I wrote : — 

 " Is there not hybridity here ? If possible, this ought to be re-found 

 and cultivated. I much doubt its being merely crispus.'" 



In 1892 the locality was again searched for the new form, but 

 in the first instance apparently without success ; one plant, liow- 

 ever, amongst the Potamogetons collected in 1892 by Messrs. 

 Kidston and Stirling struck me as being wrongly named ; it was 

 labelled, " P. ubtusifolius, Mert. et Koch. Wood Ponds, Grange- 

 mouth, Co. Stirhng, 12.6.93, R. K. & J. S. S." This plant was 

 not like the specimens collected in 1890 from the same locality in 

 general appearance, but still looked like P. obtnsifulius with very 

 faintly serrulate margins. 



Respecting these specimens I wrote to Col. Stirling: — " Tliis 

 plant is not P. obtusifulins, but is a form of P. crispus L. (possibly 

 a hybrid ?), and has been named P. serrulatus. In Mr. Bennett's 

 extremely valuable 'Notes on Potamogetons' you will find the form 

 noticed: 'P. serndatns Kegel et Maack (?) [Tent. Fl. Vssnr. p. 139 

 (1861) ). Habitus omnino P. obtusifoUi.' This is exactly the plant 

 that has often been named P. obtusifolms in Britain ; Mr. Watson's 

 herbarium at Kew contains specimens so named by him. The 

 likeness to obtiisifolius is remarkable, and the error may well be 

 excused. It is, however, a form of P. crispus L. [Journ. Bot. May, 



1893) Possibly it may be obtnsifulius x crispus? in which 



case the flower-spikes would be in all probability barren " (A. F. m 

 litt., 31.12.1893). 



In the following August an abundant supply of specimens in 

 flower came from Messrs. Kidston and Stirling, and then the true 

 character of the plant became apparent; and I think we are all now 

 agreed in regarding this Putavwgeton as a hybrid between crispus 

 and obtmifoUus. 



I have only to add that the discoverers of this interesting addition 

 to our British Pondweeds heartily concur in its dedication to our 

 friend Mr. Bennett, to whom we all feel personally grateful for the 

 untiring pains he has taken in helping us in our botanical researches. 

 For myself I would like to say many more words of gratitude, but 

 I will spare my friend. 



Mr. Morgan's plate gives as good a representation as could 

 possibly be made from the dried specimens at his command. The 

 magnified leaf shows the very faint serrulations which are princi- 

 pally found on the early stem-leaves; this and the magnified section 

 of the stem were drawn from fresh specimens. Before drying, the 

 leaves generally look less acute than those represented in the plate, 

 but this character is variable. 



B 2 



