Open fields are maintained in the park for cultural and wildlife management purposes. In these areas, as well as other open areas such as glades, the visitor may find a number of native grass species. Sadly, exotic grasses such as red fescue often dominate open landscapes at the expense of the original species, many of which are eastern outliers of prairie populations. Among the more interesting native grasses are: Big Bluestem (Andropogon gerardii) which can grow to heights of 5 - 8 feet. The stems are bluish, turning a reddish hue after the first frost. It is also called Turkey Foot due to its three part seed heads that resemble a turkey's foot. Little Bluestem (Schizachyrium scoparium) only grows to about 2 -4 feet. It turns a beautiful red in the fall. Broomsedge (Andropogon virginicus) is common in open fields and pastures around the area. It prefers acid soil and is said to be an indicator that the soil has been "played out." River Oats (Chasmanthium latiflolium) grows along the rivers. It is a valuable food for wildlife. It grows an extensive root system that helps in stabilizing stream banks against erosion. One of the most important members of the grass family along the rivers is River Cane (Arundinaria gigantea). It forms dense thickets or "Cane brakes" which help hold soil during floods as well as provide nesting habitat for the rare Swainson's Warbler.