The Structure,Elongation and Thickening of Rhizome in Nelumbo nucifera Gaertn

The seedling of Nelurnbo nucifera is erect and its internodes are very short with four Alternately arranged floating leaves. During the juvenile stage, the shoot elongates remarkably and forms the horizontal rhizome. Each leaf grows out from the dorsal side of the node of the rhizome. There are two kinds of terminal buds in the juvenile shoot. (1) vegetative bud and (2) mixed bud. The axillary scale is the derivative part of the leaf. It forms an ochrea around the terminal bud. The winter buds on the annual shoot are all mixed buds. The vessels are absent in the rhizome and no cambium exists. During tile early growth of the rhizome, the rib meristems contribute mainly to the internode elongation. Later however, divisions are seen to commence in the parenchymatous tissue of the internode. As a result of these divisions the internode becomes elongated. The tuberization of the rhizome is built up from cell divisions of three kinds of tissues: (1) primary thickening meristems, (2) cells of the vascular bundles and (3) parenchyma of cortex. But, the growth in thickness of the rhizome seems to be chiefly due to the enlargement of parenchymatous cells.