In many cases, human life ends with death and burial in the ground. Plants are just the opposite. They emerge from the earth and draw nourishment from it. For this reason, many mythological traditions associate plants with birth or rebirth and with the eternal cycle of life springing forth from death.
The magical plant or herb of immortality sought by Gilgamesh, the hero of ancient Mesopotamian mythology, provides one example of how myths use plants as symbols of life and of the healing power of nature. However, because some plants yield poisons and some die in winter, plants can also represent death and decay.
Various trees, shrubs, herbs, grains, flowers, and fruit appear in myths and legends as general symbols of rebirth, decay, and immortality. Some plants have acquired much more specific meaning in folklore. […]
Source: Plants in Mythology – Myth Encyclopedia – Greek, god, story, legend, names, ancient, tree, snake, norse, world, Chinese