Tubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to overwinter and regrow the next year and as a means of asexual reproduction. Two different groups of tubers are: stem tubers, and root tubers. Stem tubers A Stem tuber forms from thickened rhizomes or stolons. The tops or sides of the tuber produce shoots that grow into typical stems and leaves and the under sides produce roots. They tend to form at the sides of the parent pla… (More on Tuber)