The hard, outer covering of the grass seed is known as the seed coat. It protects the embryo, endosperm and the fruit of the seed, or caryopsis.
Germination occurs after the seed is watered. The water causes enzymes to breakdown and form starch. The starch is stored in the endosperm, which nourishes the embryo.
The radicle is a taillike, embryonic root that breaks through one end of the grass seed. It grows into a vast root system by absorbing water and nutrients from the soil.
Grass seeds contain one seed leaf or scutellum. Inside the scutellum is a sheath or coleoptile, which harbors the leaves. The leaves break through the seed toward the soil's surface.
Tiny flowers or florets emerge after the coleoptile is established. The florets contain the lemma, palea and awn, which disperse new seeds throughout the air and water.