Forests on the Fringe
nearly every part of the state, is thought to be originally from Texas and Oklahoma. It was brought to Missouri by American Indians for use in bow making. In southeast Missouri, Ozark witchhazel is known only from the St. Francois Mountain region.
Not long after dropping off the Ozark Plateau in southeast Missouri, you will cross a low ridge. After driving through the steep hills of the Ozarks, it is hardly cause to slow down. However, Crowley's Ridge is a unique land feature in the Bootheel, a remnant from the time when the Mississippi River followed a different channel. Evidence indicates that the Mississippi River flowed on the west side of Crowley's Ridge until recently in geologic terms, when the channel of the river changed to its present course on the east side of the ridge.
The vegetation supports this theory. Some of the species found on Crowley's Ridge and the rim of the Ozark Plateau are at the western limit of their range. Trees that seem more at home in the southern Appalachians are found here, including tulip-poplar, sweetgum, American holly, American beech and cucumbertree.
East of Crowley's Ridge are Missouri's southeast lowlands and the head of the Mississippi Embayment. This is the warmest and wettest part of the state. The flat, alluvial plain was formed by the river. Most of the region was originally forested with a dense growth of deciduous trees, many of which are typical of the Gulf Coastal Plain. The trees were cleared and the swamps drained to make the Bootheel one of the state's richest agricultural areas. A glimpse of the original Bootheel landscape can still be seen at Allred Lake Natural Area, Mingo National Wildlife Refuge, Big Oak Tree State Park and Donaldson Point Conservation Area.
Many of the trees that grow here, such as cottonwood, sycamore, willow, green ash, silver maple, hackberry, box-elder and elm, are the same species found in bottomland forests throughout the state. However, some trees found in the Bootheel are found nowhere else in Missouri.
Small differences in elevation determine which trees grow where. Completely different species will grow on "ridges" that are only one or two feet higher than the surrounding land. In the permanently wet swamps, the dominant trees and shrubs are baldcypress, water tupelo, water locust, swamp cottonwood, buttonbush and corkwood. The low flats next to backwater sloughs support water hickory, pumpkin ash, Nuttall oak and overcup oak. On higher ground where soil drainage is better, sweetgum, swamp chestnut oak, willow oak and cherrybark oak are found. Swamps are complex places with a great variety of plants, each finding its own niche in the ecosystem.
Across Missouri, you'll find many interesting niches harboring a diversity of tree and plant life. Missouri allows you to enjoy forests from other parts of the country without leaving the borders of the state.