The article “Linking Geology and Botany… a new approach” by Jane L. Forsyth taught me a tremendous amount about Ohio Geobotany.

First, The geology of Ohio can be split into two parts. The first part is categorized as the “western part” which is exclusively limestone and is glaciated. This limestone has a flat landscape and is “glaciated” due to erosion that occurred over a hundred million years ago. The limestone rock is characterized by its magnesium variety and being nonresistant in humid climates. The second part of Ohio is the “eastern part”. The eastern part is made up of sandstone which can be identified due to it being a resistant rock. The sandstone is resistant due to its difficulty to erode and is identifiable in the Cleveland region. Due to its lack of erosion, this area has predominant sandstone valleys.

Pre-erosion, the original sequence of sedimentary rock strata was layered with three different rock compositions that also had a slight tilt which formed a low arch. The bottom-most layer is composed of a thick surface of limestone, then a layer of Devonian shale, and finally topped with a layer of sandstone. Over 200 million years ago, the pressures of the low arches created the Appalachian Mountains in the east. Although once erosion started to occur, cuts exposed where the arch stood the highest which revealed the limestone that was deep within the crest in the west. The river system that occupied Ohio is called the Teays River. The Teays River flowed for around 200 million years and is the reason all of this erosion occurred in Ohio

Pleistocene glaciers invaded Ohio approximately 20,000 years ago which had created the glacial boundary. There are two types of glaciers; till (boulders) and an unsorted mixture of sand, silt, and clay. The term “glacial till” refers to geologic material such as bedrock which the glacier moved across the land and left deposits. The Pleistocene glaciers had slowed down due to the steep-sided sandstone hills of Eastern Ohio. This boundary stretches West from Northern Kentucky to the East around Canton, Ohio. The glacial boundary separates the western, glaciated region which is composed predominately of limestone and clay from the east side which is the unglaciated region composed of sandstone.

The basic substrate for plants differs from western Ohio to eastern Ohio. In western Ohio, the substrates are composed of lime and clay which is impermeable due to inadequate drainage and low oxygenation. Due to this nature, the soil is more limey than it is in the East. The substrates in eastern Ohio are composed of sandstone which is highly permeable and has a high pH due to it being acidic.

5 species of trees/shrubs limited to limestone/limey substrates (Ohio’s Lake Erie islands)-

  1. Fragrant Sumac (Rhus aromatica)
  2. Blue Ash (Fraxinus quadrangulata)
  3. Hackberry (Celtis occidentalis)
  4. Red-Cedar (Juniperus virginiana)
  5. Redbud (Cercis canadensis)


5 species of trees/shrubs limited to high-lime, clay-rich substrates (glacial till of western Ohio)-

  1. White Oak (Quercus alba)
  2. Red Oak (Quercus borealis)
  3. Chestnut Oak (Quercus montana)
  4. Chinquapin Oak (Quercus muehlenbergii)
  5. Beech (Fagus grandifolia)


5 species of trees/shrubs limited to sandstone hill (eastern Ohio)-

  1. Hemlock (Tsuga canadensis)
  2. Mountain maple (Acer spicatum)
  3. Pitch Pine (Pinus rigida)
  4. Sourwood (Oxydendrum aroboreum)
  5. Pink Ladies’ Slipper (Cypripedium acaule)


Major determinant of the distribution of each of these species-

The Sweet buckeye is found in the southern part of the glacial boundary in the unglaciated portion. Hemlock is found in the East in the unglaciated portion but can also be found in the North in cooler environments. Rhododendron is found south of the glacial boundary and they migrated there with the Teays River.

On Wednesday, May 18th our class visited Battelle Darby Metro Park!


Tall flatsedge; Cyperus eragrostis. This tall flatsedge is part of the Sedge family. The Tall flatsedge can usually be found in damp grasslands, roadside ditches, irrigation channels, gardens, parks, and other damp environments (Washington State Noxious Weed Control Board).


Eastern cottonwood; Populus deltoides. The Eastern cottonwood grows best in moist, well drained sands or slits near streams (Southern Research Station).


Cattail: Typha latifolia. The Cattail has a broad linear leaf blade and is found in shallow water (Wildflower Center).


Limestone loving plants-

Eastern Red Cedar: Juniperus virginiana. The Eastern Red Cedar is resistant to extremes of drought, the heat, and also the cold (Wildflower Center).


Redbud; Cercis canadensis. The Redbud can tolerate full sun or part shade and moderately fertile clay or sandy soil (North Carolina Extension Gardener).

Blue ash: Fraxinus quadrangulata. Blue ash can be found growing on dry, rocky limestone slopes and moist soils of valleys. It can also be found growing in mixed hardwood forests. It prefers full sun and does not do well in part or full shade (University of Minnesota The UFOR Nursery & Lab).

Fragrant Sumac; Rhus aromatica. The Fragrant Sumac is a deciduous shrub that is is fast growing, generally pest and disease-free, and drought-tolerant (Wildflower Center).


Individual assignment- invasive species-

Bastard toadflax; Comandra umbellata. The Bastard Toadflax is semi-parasitic, feeding on other plants through its rhizomes (Minnesota Wildflowers).


Common privet; Ligustrum vulgare. The Common privet  dense thickets invading fields, fencerows, roadsides, forest understories, and riparian sites (Invasive Plant Atlas).