Points of Interest:
- Explore one of the last remaining unplowed, deep-soil tallgrass prairies in Missouri.
- Spot a rare regal fritillary butterfly siphoning nectar from summer wildflowers.
Natural Features Description:
This is one of the few remaining deep soil dry-mesic prairies left in northwest Missouri. Most of northwest Missouri was blanketed with prairie such as this in 1800. Tarkio Prairie has fertile silt loam soils that extend down for five feet or more. This soil is mainly composed of loess deposits (fine silts) that were blown across the land as glaciers receded and left vast mudflats in the upper midwest from 70,000 to 18,000 years ago. Because of the great fertility of these soils most of the prairie vegetation of the rolling loess hills of northwest Missouri has been converted to row crops.
This prairie is one of only three in Missouri to protect a population of the western prairie fringed orchid, listed as threatened by the U.S. Fish and Wildlife Service. Western prairie fringed orchids are pollinated by hawkmoths of the family Sphingidae The orchid flowers are white, heavily scented and possess spurs containing nectar – all characteristics of flowers adapted to pollination by night-flying insects. The orchids depend on the hawkmoths but not vise versa. If the hawkmoths decline due to habitat loss or application of certain pesticides then the orchid would then have problems too. This is but one example of the often intricate relationships in natural communities.
Despite its small size the prairie supports over 100 native plant species including pale purple coneflower, sky blue aster, prairie willow, finger coreopsis, Culver’s root, prairie phlox, and lead plant. Dwarf chinkapin oak occurs here. This uncommon oak species occurs in prairies and savannas of the western half of Missouri. It forms thickets and can grow eight feet tall. Although a native species, it can become a problem on prairies, sometimes forming extensive thickets.