A sunflower seed is a dicot that contains the characteristic double cotyledon. The cotyledon, also known as a seed leaf, holds food reserves for the developing seed.
Monocots are marked by a single cotyledon that is contained inside their seed coat. When a monocot begins to grow, the seed leaf produces a single leaf on the new plant. A monocot leaf is long, narrow and contains veins that run up and down the length of the leaf. Its roots are unbranched and fairly fragile.
Dicots produce two leaves when they first germinate. The leaves of a dicot vary in shape and size, with the veins extending out from the center to form. Roots of a dicot are tough and branched.