The rhizome is thick and prostrate underground stem bearing nodes and internodes. The stem stores food materials so occurs as thick and fleshy. It is irregularly branched. When favourable condition approaches the terminal and axillary buds will grows into aerial shoot system. Whereas the corm is the swollen underground stem and has prominent apical bud. The apical bud grows vertically and will develop aerial shoot system but the rhizome grows horizontally under the soil surface.