This page is dedicated to the discussion regarding the class field trips to Battelle Darby Metro Park as well as Cedar Bog on Sunday, September 11th, 2022.

Part 1. Battelle Darby Creek

First off, let’s establish the geology of Ohio to understand why certain plants grow in certain places. The state can be divided roughly into an eastern and western portion where the bedrock differs. Both locations from this excursion fall into the western area, where the rock is primarily limestone. The eastern sector is dominantly underlain by sandstone, which acts as a sieve of sorts and allows water to pass through with more ease. Both rock types are relatively resistant to weathering and erosion. The western limestone driven zone is mostly flat in comparison to its counterpart. The formation of the Appalachian mountains was due to the orientation and pressures created by these differing rock types.

Prior to erosion, the arrangement of sedimentary rock layers in Ohio consisted of a layer of sandstone on top, followed by a layer of shale in the middle, then limestone beneath. The arch created by these layers stretches across western Ohio from north to south. Erosion in the west exposed the older rock formations while leaving the younger sandstone formations intact in the east. The Teays River was prominent in the west before glacial times and flowed for about 200 million years. As the glaciers began moving less than a million years ago, the river system was interrupted.

The sandstone hills which arose from partial erosion were steep enough to slow the movement of the glaciers through eastern Ohio.

Glacial till, as it’s called, is the mixture of substances that a glacier deposits as it moves across a region. The materials depend on the geology of the area that the glacier is moving through, as well as the geology of the location it currently resides. For our case, western Ohio glacial till had relatively high amounts of limestone and clay due to the bedrock composition of the region. Eastern Ohio saw more of a sand and gravel mixture, except on the edge of where the bedrocks changed. The highest amount of limestone and clay can be found on that division and becomes less concentrated as you look further away from the edge.

The substrate properties of western Ohio has higher concentrations of lime and clay, and has poor drainage and aeration. Water tends to accumulate near the surface and remains for relatively long periods of time during the wet season. The contrary is true for the dry season, very little moisture is retained in the soil. The acidity of western Ohio’s substrate is rather low, meaning it has a higher relative pH. Eastern Ohio’s substrate utilizes the sandstone for drainage and moisture retention allowing for access to cool, clean water, yet has low available nutrients and higher acidity. The latter conditions are exaggerated at higher elevations due to the dryness of the sandstone. The areas topped with shale, though, typically run off the excess water and are impermeable. This property causes droughts to become extreme.

Species limited to lime-based substrate found on field trip

American Hackberry (Celtis occidentalis): This species has a distribution which favors the conditions associated with a limestone substrate. It has toothed leaves with an uneven lobing at the base. The bark is also easily identifiable with its coarse texture.

Chinquapin (or Chinkapin) Oak (Quercus meuhlenburgii): This oak has a distinct leaf lobing which is sharper and more shallow, almost like teeth. This tree falls into our category of lime-based substrate lovers.

Blue Ash (Fraxinus quadrangulata): This species of ash is typically better at thriving in a lime setting than its other ash counterparts. Identifiable from its opposite, pinnately compound leaves.

Fragrant Sumac (Rhus aromatica): This sumac has leaves very similar to those of poison ivy, as they are closely related. It also has an apparent scratch and sniff effect and has a range within the limestone substrate.

Not pictured.

Hop hornbeam (Ostrya virginiana): This tree has a fruit which appears similar to hops. Hop hornbeam is on the list of calciphiles.

5 Species Limited to high-lime, clay-rich substrate

  1. Redbud (Ceris canadensis)
  2. Hop hornbeam (Ostrya virginiana)
  3. Chinquapin Oak (Quercas meuhlenburgii)
  4. Redcedar (Juniperus virginiana)
  5. Hawthorn (Crataegus mollis)


5 Species Limited to sandstone hill of eastern Ohio

  1. Sourwood (Oxydendrum arboreum)
  2. Hemlock (Tsuga canadensis)
  3. Blueberry (Vaccinium spp.)
  4. Scrub Pine (Pinius virginiana)
  5. Mountian-laurel (Kalmia latifolia)


Distribution of Sweet Buckeye, Hemlock, and Rhododendron

Sweet  buckeye has a distribution across the Appalachians, and thrives in moist, well-drained, and slightly acidic soil. It also does not prefer dry or clay soils. Hemlock also thrives in the highly acidic conditions with moist soil and high drainage. This is characteristic of eastern Ohio with the sandstone substrate, the unglaciated region. Rhododendron is known to live in acid sites as well. The distribution is associated with the flow of the Teays river.

Part 2. Cedar Bog

The name of this location is quite deceptive. Cedar Bog is not a bog, but a fen. The best way to remember the difference between the two is a simple phrase: bogs clog, fens flush. Cedar Bog is a very flat biome due to the glaciation and limestone bedrock. The site flushes and drains water despite being located in a limestone zone. It is ranked the highest location in Ohio on the Floral Diversity Index! The flushes of high-lime water allow for a unique array of flora.

Individual Assignment

My individual assignment was to find two plant species which maintain a symbiotic relationship.

Prickly-Ash (Zanthoxylum anericanum)

This species of ash has a particular relationship with a species of swallowtail butterfly. The larva only feed on this prickly-ash (not truly a part of the ash family) and are able to detoxify the chemical produced by the prickly-ash used to deter herbivores. This process slows the growth of the larva, exposing it to more predators, in turn defending the plant. Both species use each other in an evolved relationship where they rely on each other for development. Resulting from this effect, the species of swallowtail butterfly has been named the prickly-ash swallowtail.

Touch-me-not (Mimosa pudica)

This is more of a general symbiosis, a mutualism if you will, between the touch-me-not and many pollinator species. I chose this example because there is an added effect with this plant compared to a typical pollination. The projectile seed dispersal of the touch-me-not can be activated by the same bees (in addition to other species I suppose) which spread the pollen and germinate the pollen grains. In essence, it can be a two for one effect for the plant by spreading seeds while fertilization creates new flowers. I also really liked this photo of a bee doing just that!


High Coefficients of Conservation

Round Leaved Sundew (Drosera rotundifolia)

Coefficient of Conservation – 7!

Ohio Goldenrod (Solidago ohioensis)

Coefficient of Conservation – 9!

Shrubby Cinquefoil (Pontentilla fruticosa)

Coefficient of Conservation – 10!

Swamp Birch (Betula alleghaniensis)

Coefficient of Conservation – 10!