Structure of Corn ('Zea mays') Seed

In maize, the seed coat is fused with the ovary wall, so this technically makes it a fruit, not a seed.

As with all monocotyledonous (monocot) plants, obviously only one cotyledon is present - in maize, this is large and shield-shaped.

Members of the grass family (e.g. 'Zea', 'Avena', and 'Triticum'), plus some other monocots, have an additional structure, called the coleorhiza, covering the root tip; the coleoptile encloses the young primary shoot.

Upon germination, the radicle and epicotyl rupture the seed and enter the soil.