During germination of the seed, the plumule, which grows above the soil and forms stem, the ascending axis of the plant, and with leaves and branches constitutes the shoot. The stem develops branches, leaves, and flowers. In most plants stems stand erect. But when they are thin and long they develop:
- tendrils and with their help climb up;
- or coils round a support
- or trail along the ground as grasses
- or grow underground as in potato, ginger etc
The stem—supports branches and leaves, conducts nutrition from roots to different parts and produces flowers, fruits and seeds. Sometimes it takes the function of leaves and turns green as in cactus. In some plants stems go underground as in ginger, potato etc. Bulbs of onion and garlic are modified stems.