Red-stemmed thalia, also known as alligator flag, is a large tropical aquatic plant, found in Florida, tropical America and Africa. The paddle-shaped leaves with thick stalks can grow up to 4' tall. The complex light purple flowers emerge from large purplish-green bracts all summer long and are borne atop 10-foot stalks that are deep red at the bases. In the north these plants can be grown in pools and then brought in for the winter. They can be cut back severely for use the following spring, but they must not be allowed to dry out.