Such seedlings are characterized by having elongated hypocotyls or epicotyls. 這樣的幼苗具有伸長的下胚軸或上胚軸的特徵。
Rapid elongation of the hypocotyls after germination pushes the cotyledons above ground in plants showing epigeal germination. 種子萌發後下胚軸迅速增長,將子葉頂出地面形成地上芽。