144 



BOTANICAL GAZETTE 



[FEBRUARY 



figure, have margins fringed with long hairs and spread much more 

 widely than in our plant. Finally, the whole pistillate flower in 

 Kerner's figure is placed in such relation to the surface of the 

 water that it could be sustained there only on the supposition that 

 it is supported by a stiff stem. 



Similarly, Kerxer has figured the stamina te flower as markedly 



different from ours. It is represented 

 as having 3 equal and symmetrically 



sepals; the stamens are 

 figured with long filaments at right 

 angles and protruding beyond the 

 margins of the sepals. Tiny clusters 

 of pollen grains crown these wide- 

 spreading filaments, carried after the 



arranged 



fashion of the spar torpedo well over 

 the margins of the flower. Com- 

 pared with its companion blossom, 

 the staminate flower is figured as 

 many times larger than in our plant. 

 These and many other minor 



points of difference suggest that 

 Fig. 6.— Release of tension on Kerner's account is highly general- 



the scape has permitted submerged fc^j and per haps intended to convey 

 flowers to come again to surface; , . e . „« 



pollen and some entire staminate ^ a general account of the pollina- 

 tion in this plant. It may only be 



accidental that most of the depar- 

 tures from the conditions found in our plant are necessary to make 

 possible his proposed plan of pollen transfer. On the other hand, 

 it may be that the European plant is essentially different from ours 

 of the same name ; if so, ours should be described as another species. 

 That there may be considerable difference between the forms on the 

 two continents is further supported by Turpin's (6) figures, which 

 show slender stamens somewhat divergent, and 



flowers may be seen on stigmas. 





stigmas 



very 



different from those found in our form. In so far as one can 



depend upon published figures, it would seem 

 divergent plants are included in the species 



pi rati 



