There were four main types of prairie grass in Illinois. They are switch grass, Indian grass, big bluestem , and little bluestem. Switch grass has an open head. It's also bushy, and grows in wet areas. The roots may be 11 feet deep.
Indian grass grows in drier areas than switch grass.
Big bluestem grows up to nine feet tall. The early settlers had to stand on their saddles to see over it. It grows in medium wet areas. The roots may be seven feet deep or more. In June, July, and August, the stem turns to bluish green.