There are two basic patterns for seedling emergence.

Seedlings with an epigeous pattern produce an hypocotyl hook that emerges through the ground. The cotyledons are raised above the ground.

In hypogeous germination, the cotyledons remain below the ground and the first structure to appear above the ground is the epicotyl. Arrows indicate location of cotyledons.

Photo showing a time lapse example of epigeous pattern germination, with the cotyledons raised above the soil line. Photo showing a time lapse example of hypogeous germination, with the cotyledon shown below the soil line.