1. Support and orient the leaves in a manner that they are exposed to maximum sunlight and for efficient gaseous exchange during photosynthesis and respiration.
2. Conduct water and minerals from roots to leaves and manufactured food from leaves to different parts of the plant.
3. Bear flowers and fruits.
1. Storage - Stems store food and water in some plants. For example: potato
2. Perennation - The underground stems help tide over the unfavourable growing periods. For example: ginger
3. Vegetative propagation - Stem can be a means of vegetative propagation. For example: rose and sugarcane
4. Photosynthesis - In certain plants like xerophytes (desert plants) where leaves are reduced, the stem takes up the function of photosynthesis. These stems possess chlorophyll. For example: Opuntia
5. Protection - In some plants the axillary bud modifies into thorn and protects the plants from grazing animals. For example: citrus, Duranta
6. Climbing - Tendrils or hooks are modified branches or buds. They coil around the support and help the plant to climb. For example: grape vine