There are three distinct types of leaves: the submerged leaves, which are sto-mateless; the floating leaves, with stomata generally confined to the upper surface 5 the aerial leaves are usually large, with numerous stomata.The rhizomes are creeping, with numerous branches. By means of these branches,the rhizomes spread rapidly through the mud. Parts of the rhizome become fleshy tubers, which serve for vegetative propagation of the plant.The air chambers and passages are well developed in all the organs.The ...