POLLINATING AGENTS 123 



and submerged, and bears long, ribbon-shaped clusters 

 of radical leaves. The male flowers (A) are sessile, 

 and situated low down amongst the radical leaves. 

 The female flowers (b), on the other hand, are borne 

 upon long stalks, which, remaining spirally coiled, 

 keep the flowers under water. When the male flowers 

 mature, they get detached from the plant and ascend 

 to the surface of the water, on which they float freely, 



A B 



Figf. 108. — Pata-shaola {Vallisneria spiralis) 



being swayed hither and thither by the wind. By a 

 curious instinct the stalks of the female flowers are 

 at the same time uncoiled, bringing the hitherto sub- 

 merged female flowers to the surface. "After selecting 

 their husbands, the female flowers sink to the bottom 

 of the tank by (again) coiling up their long stalk." The 

 fruits ripen under water and germinate in the mud. 

 Hydrilla verticillata is another common submerged 

 dioecious weed (a kind of jhangi) of our tanks. The 

 short-pedicelled male flowers are solitary. At the time 

 of pollination they separate from the plant and float 



