The beginning of growth of the seed into a new plant is called germination.
The embryo formed is later differentiated into plumule (shoot part), radicle (root part) and cotyledons.
Shoot portion between cotyledon and plumule is known as epicotyl.
Root portion between cotyledon and the radicle is termed as hypocotyl.
Epigeal germination:
The type of germination in which hypocotyl elongates rapidly and arch upward pulling the cotyledons which move above the soil is called epigeal germination.
Gourd and castor are examples of epigeal germination.