Ohio geobotany

Ohio is mainly divided into two parts. The western part is underlain by limestone (including broad areas of its magnesium- containing variety, dolomite), a rock type that is relatively nonresistant in this humid climate. As a result, through the millions of years that have elapsed since the erosion of these rock first b egan, this part of Ohio has been worn down to a comparatively flat landscape. In contrast, eastern Ohio is underlain by sandstone, a relatively resistant rock, which is underlain by shale to the west and throughout the Cleveland area. Erosion of the sandstone is accomplished mainly by solution of the neutral cement holding the grains together by water seeping down through the rock.

The reason for the contrast in kinds of rocks between the western and eastern parts of Ohio is because the original sequence of the sedimentary rock strata in Ohio was a thick series of limestone layers overlain by shales which were in turn overlain by sandstones, and was gently tilted into the form of a low arch before erosion began. The arch was a product of those pressures which, approximately 200 million years ago, created the Appalachian mountains to the east. Subsequent erosion has cut deepest where the arch stood highest, exposing the oldest rocks along its crest which extends generally north-south through western Ohio. These oldest rocks were the limestones which are found throughout western Ohio whose nonresistance has resulted in the erosion of that part of the state down to a nearly flat plain. Farther east away from the crest of the arch, the youngest rock layers, the resistant sandstones, were not removed, erosion having cut deeply into the rock strata but not having eroded it completely away, resulting in the sandstone hills characteristics of this area. Typical of the cleveland region, where the sandstone is underlain by shale, Most of this erosion of all the limestone in western Ohio and of the shale and sandstone in the east was accomplished by a famous preglacial stream, the Teays (pronounced “Taze”) River. This river was present in Ohio for a very long time about 200 million years ago. These streams continued to erode the land throughout the entire length of that long interval of time, their activities curtailed only by the advance of the glaciers of the Ice age (Pleistocene Epoch) less than a million years ago.

These glaciers were greatly slowed down by the steep-sided sandstone hills of eastern Ohio, so the glacial boundary there is no farther south than the latitude of Canton. In contrast, on the broad limestone plains of western Ohio, where there was nothing to hinder the advance of the ice, it extended as far south as northern Kentucky.


Deposition by the glacier was of two kinds: an unsorted mixture of sand, silt, clay, and boulders called till, accumulated directly by the melting of the ice, and sand and gravel materials deposited by the glacial meltwater. The composition of till reflects, in large part, the nature of the geologic materials over which the glacier moved that left the deposit. Thus, in western Ohio the glacial till is rich in lime and clay, products of the glacial abrasion of the limestone bedrock. In eastern Ohio, on the other hand, most of the till contains very little lime and clay, although near the margins of the area of sandstone hills, where the ice moved from limestone bedrock onto sandstone, the till is higher in both lime and clay than it is elsewhere in eastern Ohio.

On the plains of western ohio the most common substrate is limy, clayey till which provides a relatively impermeable soil, high in lime but poorly drained and inadequately aerated. On this soil, water does not soak in very fast but tends to remain on the surface, creating low oxygen availability during wet periods and bad drouths during dry spells. The supply of plant nutrients here is comparatively abundant. Where the glacial till is thin or absent, a condition encountered only locally, the soil on the limestone is generally very shallow, very high in lime, rich where it is not too thin, but very dry due to excessive drainage down through the natural solution openings in the soluble limestone. In eastern ohio on the other hand, the very permeable sandstone bedrock, where it is exposed, produces a very acid, low-nutrient substrate which is especially dry on the tops of the hills. Locally the sandstone crops out at lower elevations, Here, though it is also acid, it provides a supply moisture that is continually both available and cool because it comes from springs, the water of which has perlocated down through the permeable sandstone and emerged deep in the valleys without being sunwarmed. The shale present beneath the sandstone in some areas also produces a generally acid low-nutrient substrate. However, unlike the sandstone, it is impermeable. As a result surface water tends to run off rather than soak in, making it an especially drouthy substrate during prolonged dry spells. In addition shale may be present as layers within the sandstone; where this happens, the cool acid water moving down and emerges on the hillsides as springs. Where the sandstone is mantled by till, the amounts of clay and lime in the till result in less acid, more moist, and more nutrient-rich soils. The till which occurs near the margins of the sandstone area contains greater amounts of clay and lime, resulting in substrates more like those formed in the western Ohio.

The five species of trees/shrubs  that have a distribution generally limited to limestone or limey substrates such as Ohio’s Lake Erie islands are: Blue Ash, Hackerberry, Hawthorn, and Chinquapin oak. Also, I did find two of these species on my trips.

Blue Ash

Blue Ash, Fraxinus quadrangulata, is a flowering plant species which is indigenous to the midwestern united states. It grows in moist valley soils and serves as an important food source for frogs.


Its is commonly called the sugarberry as well and its scientific name Celtis laevigata. This is deciduous medium-sized tree native to North America. Often found near water- on floodplains, along rivers and streams.

Five species of trees/shrubs that have a distribution generally limited to high-lime, clay-rich substrates developed in the thick glacial till of western Ohio include the blue ash which is an occasional representative. Most common of the tree species occurring on these till plains are: sugar maple (Acer saccharum), beech (Fagus grandifolia), red oad (Quercus borealis), shagbark hickory (Carya ovata), together with white oak (Quercus alba). 

Five species of trees/shrubs that have a distribution generally limited to sandstone hill of eastern Ohio are: chestnut oak (Quercus montana), sourwood (Oxydendrum arboreum), scrub pine (Pinus virginiana), pitch pine (Pinus rigida), hemlock (Tsuga canadensis). 

The sweet buckeye is one of a number of species which does not occur anywhere inside the glacial boundary. The reasons for such restrictions in distributions are not known, but may have something to do with problems of repopulation, by these plants, of the clayey, high-lime glacial hills in the short time since the ice left Ohio. These plants also do not extend even as far north as the glacial boundary in eastern Ohio, perhaps climate is the controlling factor here, for no geologic discontinuity is known along the edge of its distribution. The hemlock on the other hand is also present in the unglaciated eastern Ohio,  but its distribution extends far to the north, to the north of the glacial boundary in that area. The reason for this more extensive distribution appears to be its restriction to continuously cool, moist environments such as are found in the bottoms of deep valleys cut into sandstone and watered by cool spring water in the south, or such as occur in valleys in the north which contain some till but remain cool and moist because they are deep and open to the north. There are some plant species present south of the glacial boundary whose distribution might suggest that they belonged to the mixed mesophytic association in ohio, even though they do not occur everywhere throughout the unglaciated area. An example is the rhododendron.

Some species that I found at the battelle darby creek park….

Slough sedge

Slough sedge, Carex obnupta, is a fast-growing type of sedge grass that is often used for erosion control. It prefers full sun to part shade and moist growing conditions like its native habitat, the wetlands of the western United States.

Fowl mannagrass

The fowl mannagrass, Glyceria striata, native to North America. This common species of bunchgrass is found in wet areas and is considered a good food source for horses and cattle.

Blue Ash

We talked about blue ash earlier…scroll to the top!!!

Black Ash

Black ash, Fraxinus nigra, is a deciduous tree that grows to 40-50 feet tall. It has an attractive dark gray or brown bark and its limbs ascend upward to form a small sanopy. It prefers full sun to partial shade and thrives in cold climates. It is adaptable to wet sites but is responsible to emerald ash borer.

Then I found two species of elm…

American elm

The american elm also known as, white elm and water elm, Ulmus americana. It is a deciduous hermaphroditic tree which can be found in a variety of habitats- swamps, low-lying lands, areas surrounding rivers, hillsides, and highlands.

Slippery elm

The slippery elm has a lot of common names such as, red elm, sweet elm, indian elm, and etc. also the scientific name is, Ulmus rubra. An elm tree native to the US, the inner bark has a slippery texture that gives the tree its name. The wood is fibrous and can be turned into excellent twine or rope.

New england aster

New england aster, symphyotrichum novae-angliae. A flowering plant native to North america. It is widely cultivated for ornamental horticulture and as a garden plant. There are over 70 cultivators of new england aster.

Stiff goldenrod

The stiff goldenrod, Solidago rigida. It is named for its rigid stems and showy yellow flowers which attract butterflies. The plant produces a tufted seed that is dispersed by the wind.

Some plants that I found at the Cedar Bog….

Garden balsam

The garden balsam, Impatiens balsamina, is also known as the touch- me- not plant native to Europe. Attracts pollinators as well as nectar-feeding plants.

White snakeroot

White snakeroot, Ageratina altissima, contains a toxin called tremetol which causes a potentially fatal illness. It is toxic to all animals and horses and livestock are most vulnerable. Humans can die too if ingested in large quantities.