220 



THE JOURNAL OF INDIAN BOTANY. 



or slow moving fresh water of varying depths either as a free floater 

 or rooted in the mud like a swamp plant. It is this indifference 

 with regard to the habitat which makes it not the only troublesome 

 weed that it is but also occasions the formation or not of bladders 

 which are the most striking peculiarity about the plant. An ex- 

 amination of the plant in different surroundings will disclose four 

 principal types, viz., (l) all the leaves of the plant with bladders ; (2) 

 all without bladders, (3) outer bladdered and inner bladderless, and 

 (4) outer bladderless and inner bladdered. 



Morphology : — In its best development the bladder is a rounded 

 or pear-shaped structure 1 to 1^ in. in diameter, representing the 



whole of the leaf stalk and separated from the lamina by a short 

 neck and narrowed at the base. From ten to fifteen leaves become 

 closely aggregated together so as to form a rosette, and from the 

 axils of many of the leaves new shoots arise which end in similar 

 rosettes and originate fresh shoots in their turn. In this way are 

 formed chains of sympodes radiating in all directions and covering 

 a wide expanse of water in a surprisingly short period. Along with 

 these there are also plants in which the bladders attain various 

 stages of development leading to those which show only a slight 

 swelling in the stalk or to its complete disappearance. These do 



