There are over 6000 species in the grass family. Included in the graminae family is the grass for lawns but also grains like wheat, rice and oats. What makes grass unusual is that growth happens from the crown of the plant. It grows from the crown at the soil level up rather than from the tops of the plant. Ornamental grasses add a sense of movement to a yard. They come in sizes as short as 6 inches to over 10-feet tall. Annual grasses are those that have to be ...