The Ozark region is floristically diverse and supports a number of distinctive vegetation types (including oak-hickory forest and beech-maple forests) and habitats (such as cool, moist ravines and glades of thin soil and exposed bedrock). Geographically, the Ozarks are further south than Chicago, but the region's many species thrive at The Morton Arboretum. Additionally, plants occurring in the areas of the Ozarks characterized by limestone and dolomite have a good chance of adapting to the high pH soil of the Midwest.
This collection is located on the West Side of the Arboretum. It was designed in 1932 by O.C. Simonds, the Arboretum's Landscape Architect at the time, and surrounds Lake Jopamaca. The site of this collection includes low-lying areas with seasonal flooding, as well as water edges and small hills for upland plants. This variation in topography within the site makes it an appropriate landscape to incorporate the diverse vegetation of the Ozark region within a relatively small area. A total of 132 different kinds of plants are assembled in the Collection, representing over 470 plants.
A notable species in this collection is the bald cypress (Taxodium distichum) growing on the edge of Lake Jopamaca. This water-loving tree drops its needles in the winter months and is known for its buttressed trunk and "knees" or root projections around its base. A colony of pawpaw (Asimina triloba) is growing in a low-lying area of this collection as part of the understory. The fruits from this colony are an excellent food source for wildlife.