Aquarium Plants 49 



The male flower has a very short stem and, 

 before opening, resembles a small green cap- 

 sule. To cause the fertilization, the male 

 flower separates itself from the stem and 

 mounts to the surface of the water, where 

 it opens, and floating, carries the pollen to 

 the female flower. After the fructification 

 is accomplished, the stem of the female 

 flower contracts into a spiral, thereby sub- 

 merging it, so that the seed ripens under the 

 water. 



Outside of the flowering season it is not 

 easy to distinguish the sexes. Usually the 

 leaves of the female are broader and darker 

 than those of the male plant. There is also 

 a difference in the formation of the roots. 

 While the root fibers of the female plant are 

 bunched around a bulblike knot, those of the 

 male plant are placed on a somewhat elon- 

 gated central stem. 



The Valisneria is easily propagated from 

 runners which extend from the older plants 

 in all directions. If planted in an aquarium 



