Stem

Part of the plant above soil is called stem or trunk. This is the most important part of shoot system with stamen, buds, leaves etc. Most of smaller parts have soft and green stem which move easily.

Shrubs and trees have stem or trunk method made up of tough and hard wood. The outer surface of wooden stem has bark. 

Functions of Stem

1. Gives support - trunk supports branches, leaves, fruits and flowers.
2. Carrying - they carry absorbed water and mineral salts to leaves.
3. Storage of food - they transport food prepared by leaves to the stem or trunk of the plants. 
4. Some of the plants transform, their bud into long green leaves like structure, the work of these leaves like structure is to do the work of photosynthesis. Example - nagfni, cactus, etc.