Epigeal germination: Seed germination in which the cotyledons (seed leaves) are raised above the soil surface.*
These arugula seedlings raise their heart-shaped cotyledons above the soil surface to begin photosynthesis before their first true leaves appear. Many plants germinate in this way, for example, beans and sunflowers.
*Capon, B. (2005). Botany for gardeners (Revised ed.). Portland: Timber Press.