Battelle Darby Metro Park

In broad terms, the geology of the state of Ohio has two parts: one part on limestone and one part on sandstone.  The limestone portion is on the western side of the state; it is flat due to how easily limestone erodes.  The sandstone half is on the eastern side and does not erode as well.  This has led to a hilly landscape as the shale around it wore away leaving the tall mounds of sandstone.

The original sequence of sedimentary rock strata was, from top to bottom,  sandstone, shale, and limestone. These layers formed an arch that resulted in the original Appalachian mountains in the east. The low-lying toe of the arch were limestones and the crest of the arch lay further east and was made of sandstone. The Teays River caused erosion of the landscape during its 200 million years of flowing.  The limestone was eroded into a plain and cut into sand stone forming hills.  This river system was curtailed by the advance of the Ice Age glaciers.

Pleistocene glaciers moving through Ohio 20,000 years ago were slowed down by the steep sandstone hills, which caused a glacial boundary across Ohio.

Glacial till is a mix of sand, silt, clay, and boulders which is accumulated by the melting of ice and deposited by the meltwater.  Glaciers that moved over different materials will have different compositions of till.  Western Ohio has glacial till that has abundant lime and clay from the limestone bedrock the glacier traveled over, while eastern Ohio has very little lime and clay.

The plant substrate for plants in Ohio varies based on this glacial till.  Western Ohio substrate is limy and clayey, with poor drainage and aeration, but abundant nutrients.  Eastern Ohio substrate is more acidic, has plenty of drainage and aeration, and is low in nutrients.

Some plants are limited to living on only one kind of substrate.  Trees and shrubs that are restricted to limestone/ limey substrates are: redbud, red-cedar, fragrant sumac, hackberry, blue ash, hawthorn, chinquapin oak, and hophornbeam.

American Hophornbeam

The leaves are alternate and simple. The trees have catkins, and the females produce fruits that resemble hops from beer production.

Fragrant Sumac

Fragrant sumac has very poison ivy-like leaflets, but they lack the side lobe that gives the mitten appearance. The leaves are palmately compound and alternate with serrated edges. It is more of a shrub than a tree.

Parsley Hawthorn

Hawthorn leaves are simple, lobed, and serrated.  It has small fruits. The tree stays fairly small with wide branches.

Swamp White Oak

Swamp white oaks have rounded leaves that have wavy lobes. The leaves are alternate and simple.

Trees and shrubs that live on high-lime clay-rich substrates are: sugar maple, beech, red oak, shagbark hickory, white ash, swamp white oak, and pin oak.

White Ash

White ash leaves have 5 leaflets that are widest at the middle and serrated.  The veins of the leaflets are feathered.

Trees and shrubs limited to the sandstone hill of eastern Ohio are: chestnut oak, sourwood, scrub pine, pitch pine, hemlock, and mountain maple.

The major determinant for sweet buckeye distribution is the glacial boundary, the tree does not occur inside the boundary, whereas hemlock does populate within the glacial boundary in the moist valley-bottom sites. Rhododendron is present south of the boundary and was determined by the Teays system.

Cedar Bog (that isn’t a bog)

Cedar bog is NOT A BOG it is a fen.  Fens are characterized by water that comes from the ground and flows through the landscape, the constant wetness of the area is caused by this. Cedar Bog has limestone in the water that causes it to be alkaline.  All of the substrate in Cedar Bog was quite wet and it changed quickly between more wooded areas and fields of sedges.

I was assigned to find two pinnately compound plants while at Cedar Bog:

Black Ash

The leaflets of the black ash do not have their own “stem” and are directly attached.  The edges of the leaflets are serrated, and they are long and lance-shaped. Black ash has been used for many years in indigenous cultures to make baskets thanks to its pliable wood.

Green Ash

Green ash leaflets do have their own “stems” and also have serrated edges.  The leaflets on green ashes are shorter and rounder than on black ashes. Green ash often has functioned as a pioneer species, but will also grow at almost all stages of forest development.

Poison Sumac

Bonus third pinnately compound plant! Poison sumac leaflets have smooth edges and turn red in the fall. The stems of the leaves are reddish, and the branches will have clusters of small fruits that are green in the spring and summer and white in the fall. A fun, terrible way to identify poison sumac is by touching it and seeing what happens.  If your skin is very painfully irritated it was probably poison sumac and you’ll feel pretty silly. I cannot recommend this method.