Question

what is the functions of underground roots?

Answer 1

1) Perennation- to tied over unfavourable period.
2) Storage of food- food stored is edible.
3) Vegetative reproduction- new plants are being produced from underground stem.

Answer 2

Underground roots serve about 7 different function for a plant.
1. anchorage and support
2. absorption and conduction (nutrients, water)
3. Storing water and nutrients
4. photosynthesis (not all, but some. Especially those found in mangroves)
5. Aeration (plants that grow in dense water)
6. Movement (roots pull down into the growth where the environment is more stable)
7. Reproduction
You can find more information on these purposes at: http://www.cropsreview.com/plant-root-system.html