When environmental factors such as temperature, moisture, oxygen and sometimes light are favorable. a viable seed will begin to grow, or germinate, as long as it is not in a state of dormancy. The radicle, a rudimentary root, emerges from the seed first followed by the plumule or first shoot. Germination is either hypogeal (cotyledons remaining below ground) or epigeal (cotyledons emerging above the soil surface). The following image shows both types of germination in monocot and dicot seedlings. Daylily seed germination is hypogeal, with the single cotyledon remaining in the seed below the ground.
Image by Tim Fehr, used with permission
