The Geobotany of Ohio

The geology of Ohio can be divided into two different parts. The Western part and the Eastern part. The Western part of Ohio is underlain by limestone while the Eastern part is mostly underlain with sandstone. Over the course of 200 million years the western part of Ohio has been worn down to a flat landscape. As far as the Eastern part goes the sandstone is resistant to a lot of water erosion so erosion is a very slow process. This has resulted in a landscape of sandstone hills throughout the Eastern part of Ohio.

There is a reason that these rocks are so contrasted in the various parts of Ohio that we see. The original horizontal sequence of sedimentary rock strata was gently tilted in to a low arch before erosion began. The original sequence of sedimentary rock strata started with the oldest rocks that was discovered by subsequent erosion . The oldest rocks were limestone that are found in western Ohio which is why the constant erosion has made that part of the state into a flat plain. The eastern part of the state contain the youngest part of the state where the sandstone character is responsible for the hills found in north east Ohio. In the Cleveland area the sandstone is underlain by shale. A lot of the erosion and the of the limestone in Western Ohio and the shale and sandstone in Eastern Ohio was because of a very important river in Ohio that flowed for 200 million years, the Teays river. However, the river flow was curtailed by glaciation of the Pleistocene Epoch (Ice Age) less than a million years ago.

The Pleistocene glaciers were greatly slowed down by steep-sided sandstone hills of Eastern Ohio. According to Jane L Forrsyth in her paper “Linking Geology and Botany … a new approach” Glacial till is a term that can be defined as an unsorted mixture of sand, silt, clay, and boulders that is accumulated directly by the melting of the ice and the sand and gravel materials deposited by the glacial meltwater. Till is different in the Eastern and Western parts of Ohio. In the Western part of Ohio the glacial till is rich in lime and clay because the glacier moved over that part of the state. Contrast this to the Eastern part of Ohio where the till contains very little lime and clay.

Plants in eastern and western Ohio have contrasting substrates due to the minerals surrounding the land in the dfferent parts of the state.  This seems obvious but let’s go over some of the basic substrates in the states and plants that associate with them. In the western plains of the state the most common substrate is limey, clayey till that provides impermeable soil that is also high in lime. It is also however, poorly drained and not very well aerated. With this type of soil the water does not soak very fast and likes to stay on the surface. This makes very low oxygen availability. during wet periods. The glacial till however provides the plains with an abundance of nutrients.

In the eastern part of Ohio the exposed sandstone bedrock produces a very acid, low nutrient substrate that makes the top of hills very dry. Water cannot penetrate through the sandstone so it tends to run down and creates especially dry droughts. It may be even worse because if there is shale present beneath the sandstone then water cannot go deeper and emerges as springs in the hillsides.



Trees/shrubs that have a distribution generally limited to limestone or limey substrates:

  • Hawthorn (Crateagus mollis)


  • Hop Hornbeam (Ostrya virginiana)


  • Red-cedar (Juniperis virginiana)


  • Blue ash (Fraxinus quadrangulata)


  • Chinquapin Oak (Quercus muehlenbergii)


Trees/shrubs that have a distribution generally limited to high-lime, clay-rich substrates developed in the thick glacial till of western Ohio:

  • Sugar Maple (Acer saccharum)


  • Beech (Fagus grandifolia)


  • Red Oak (Querces borealis)


  • Shagbark Hickory (Carya ovata)


  • White Oak (Quercus alba)


Trees/shrubs that have a distribution generally limited to sandstone hill of eastern OH:

  • Chestnut Oak (Quercus montana)


  • Sourwood (Oxydendrum arboreum)


  • Scrub pine (Pinus virginiana)


  • Pitch pine (Pinus rigida)


  • Hemlock (Tsuga canadensis)


The major determinant of the distribution of sweet buckeye when contrasted with hemlock,  hemlock when contrasted with sweet buckeye and rhododendron is where these different trees are grown. The sweet buckeye (Aesculus flava) only gows in the Southeastern portion of Ohio while it is very rare in places like North East ohio. The reason for this is unknown but could be related to the climate. The Eastern Hemlock (Tsuga canadensis) grows mostly on the sandstone ridges and valleys of the unglaciated Eastern part of Ohio. However, hemlock also spreads to the Northern stretches of unglaciated land. This tree prefers cool, moist environments like the deep valleys sandstone or the valleys in the north where more limey substrate are located in upper Ohio. The Rhododendron (Rhododendron maximum) really only occurs south next to the glacial boundary. The cause for this is caused by  the flow of the Teays river, as the Rhododendron migrated along the waters of the Teays river.

Battelle Darby Metro Park highlights

The summer of 2022 EEOB 2210 class took a trip to the Battelle Darby Metro park. We started our adventure in the wetlands where we saw a variety of monocots that included grass, sedges and rushes.

To the right you can see Tall flatsedge (Cyperus eragrostis) Sedges are a super important monocot that can be characterized by its triangular shaped leafs while grasses have more of a rounder shaped leaf that is distinguishable from sedges.

Pictured below is another type of of moncot called cattail that is a type of grass that we found here in the wetland park. Neat!

Throughout the wetlands we were also able to find Eastern Cottonwood (Populus deltoides). You can charcterize

this tree by the toothed leaves and reddish branches depicted below. The tree here is relatively young but notice the distinguishable characteristic that sets it apart from the other plants around it. Thoughout the wetlands we were also able to find Crack Willows (Salix fragilis) trees that bring me to the assignment that I was assigned to on this trip. Invasive plants! Invasive plants are plants that are not native the the area you may be foraging. This can be bad news for the natural ecosystem as it could bring harm to the native plants surrounding the area. More on this later when I list off a couple of invasive plants I found and their effects of the flora surrounding the area.





Monocot flowers

One of the thins that Dr. Kilps had us look out for at the Battelle Darby metro park where monocot wildflowers in the area. Monocot wildflowers can be identified with their parallel veined leaves and their cotyledon fruit. One of the first monocot flowers that I was able to find was the Spiderwort flower (Tradescantia virginiana). It gets it’s name from its apperance of a spider. The purple leafs are of the utmost importance to this flower in order for bees to be attracted to it so it could pollinate.

Another monocot flower that we saw on the trip was the False Solomon seal flower (Maianthemum racemosum). This has smooth leaves and is its flowers are a sort of pale yellow/white color that form in clusters. Dr. Klips told us that False solomon’s seal was used by the native people for food and they also used it as medicine particulary in both the leaves and the roots.







Limestone loving Plants

The Batelle Darby trip was cool because we got to experience limestone loving plants in nature rather than reading about them in a paper. Field experience is always very cool. Here are some limestone loving plants that we saw during our trip to Battelle Darby.

Sedge (Carex) is also a limestone loving plant. We found some in the wetlands. They are pretty common.

Eastern Rosebud (Cercis canadensis) Note the heart shaped leaves that distinguish this from other plants.

Branch of Blue ash (Fraxinus quadrangulata) Note the four ridge shape that is very common in ash trees. Especially this one.

Blue ash branch (Fraxinus quadrangulata) The opposite leaves and leaf shape make this tree very distinguishable from the others.



Hophorn bean (Ostrya) A lime loving plant that was abundant in the Battelle Darby park.





Invasive Plants:

We talked about invasive plants and their definition. Here are two invasive plants that we found at Battelle Darby that I was assigned to.

Privet (Ligustrum sinense) is an invasive plant to the biodiveristy of Ohio that is recognizable with it’s small leaves that thrive in full sunlight and tolerate heavy shade.

Honey Suckle (Amur honeysuckle) A dominant and aggressive honeysuckle that reduces the natural biodiveristy of the area.



Other cool photos:

Here are some other miscellaneous photos that I found interesting.

Dames Rocket (Hesperis matronalis ) pretty…

Marvelous moss!


Here it talks more about the Big Darby Creek.

Mayapple (Podophyllum peltatum) with umbrella leaves. Very characteristic.





















American Columbo (Frasera caroliniensis) Check out those leaves!


Credits for this webpage include Jane L. Forsyth’s article “Linking Geology and Botany … a new approach” , Dr. Kilps and his wondeful instruction during this field trip, Lawrence Newcomb’s “Wildflower Guide” and George A. Petrides field guide on Trees and Shrubs