13. Carrots and Beetroot Carrots and beetroot are thickened tap roots which have very few lateral roots. Both are biennials i.e. they only grow for two years. In the first year they store food manufactured by their leaves in their tap root, and in the second year they use the stored food to produce flowers (called bolting). We harvest the carrots or beetroots before they bolt.
14. Ginger Ginger is a rhizome - a type of stem which grows horizontally just under the surface of the ground. Leaves grow from buds at the nodes on the stem. The stem is thick and fleshy and stores reserve food for the plant.
15. Potatoes This is likely to trick many people. Potatoes are not roots but underground storage stems which are formed when the growth point of an underground stem, a rhizome, almost stops lengthening and increases greatly in thickness. This forms an underground storage organ which stores large quantities of starch.
16. Sweet Potatoes Sweet potatoes are the greatly thickened roots of the fibrous root system of the sweet potato plant which contain reserves of starch.
17. Onions and Garlic Onions and garlic are bulbs . A bulb is an underground storage organ which consists of a very short stem on which fleshy bases of the leaves store food for the plant.