Geobotany of Ohio
The geology of Ohio is able to be divided into two parts. The western part of Ohio is underlain by limestone, and the eastern part is underlain by sandstone. Limestone is a rock type that is relatively non-resistant to a humid climate, whereas sandstone is relatively resistant. Limestone’s non-resistance has resulted in western Ohio being eroded nearly down to a flat plain. Meanwhile, the sandstone’s resistance in the east have resulted in sandstone hills.
The original horizontal sequence of sedimentary rock strata in Ohio were a top layer of sandstone, overlaying shales, which overlaid a thick series of limestone. These layers were gently tilted into the form of a low arch before being eroded. About 200 million years ago this arch created the original Appalachian mountains to the east. The rocks stood highest north to south from western Ohio. In the east, where the sandstone hills are located is where the arch was the lowest. Most of the erosion I’ve discussed was accomplished by a pre-glacial stream known as the Teays River. This stream was present for about 200 million years. This stream eroded the land throughout the entire time it was present, and its activity was curtailed by the advance of the glaciers in the Ice Age.
Pleistocene glaciers entered Ohio about a few hundred thousand years ago. They were slowed down by the steep-sided sandstone hills of eastern Ohio, stopping it from going father south than Canton. However, on the broad limestone plains in western Ohio, there was not much stopping the glacier, and the glacial boundary there went as far south as northern Kentucky.
Glacial till is a deposition left by the glaciers passing through. It was an unsorted mixture of sand, silt, clay, and boulders. In western Ohio, the glacial till is rich in lime and clay. In eastern Ohio, most of the till contains very little lime and clay. Due to the composition of these specific areas, on the western plains the substrate is limey and clay-filled, resulting in relatively impermeable soil that is poorly drained and inadequately aerated. Plant nutrients in this substrate are relatively abundant. In eastern Ohio, the substrate is very dry and acidic, and lacking in nutrients.
5 Species of Trees and Shrubs in High-Lime, Clay-Rich Substrates
Scientific Name: Fraxinus quadrangulata
The blue ash was one of our trees that grew in limy soil. We saw it growing in the Batelle Darby woods park. Blue Ash is a tree that allows good shade for areas like parks and residential areas. Early colonists used the inner bark of the tree and the sap for blue dye. When the sap is exposed to air it turns a blue color. (Linked here)
Scientific name: Quercus muehlenbergii
This oak was one of the lime-loving trees that we encountered on this trip. This was also found in Batelle Darby woods park. Early pioneers used the wood from this oak’s straight wood to make thousands of miles of fences in Ohio, Kentucky, and Indiana. They were also used to fuel steamships and as railroad ties. (Linked here)
Scientific name: Rhus aromatica
On our trip, we encountered Fragrant Sumac, another lime-growing tree. This was found in Batelle Darby woods park. Fragrant sumac has small, fleshy fruits that are harvested to make a lemonade-like drink. The leaves have been used for colds, stomach aches, and stopping bleeding. It has also been used as treatment for dysentery. (Linked here)
Scientific name: Celtis occidentalis
The Hackberry was the fourth tree that we encountered that grew well in the lime-filled substrate of western Ohio. It was easily recognizable for its flat leaves. The hackberry was traditionally used for many medicinal and food purposes. The bark was used to regulate menstrual cycles, colds, and sore throats. The fruit was often mixed with fat and corn to produce a porridge-like substance and it was also pounded into a paste and baked in the oven. (Linked here)
Eastern Hop Hornbeam
Scientific Name: Ostrya virginiana
The Eastern Hop Hornbeam is a tree that enjoys growing in substrate with lots of limestone. This tree was encountered immediately at Batelle Darby woods park. This is in the Birch family. It has elliptic, double-toothed leaves. The wood and bark were traditionally used for medicinal purposes. Teas or infusions made with the bark can be used topically for aches and pains, including full-body baths to treat sore muscles or arthritis, and as a mouthwash for toothache. (Linked here)
Species of Trees and Shrubs That Grow In High-lime, Clay-rich Substrates Developed in the Thick Glacial Till of western Ohio
Scientific Name: Acer saccharum
Scientific Name: Fagus grandifolium
Scientific Name: Quercus borealis
Scientific Name: Carya ovata
Scientific Name: Quercus alba
Species of Trees and Shrubs That Grow In Sandstone Hill
Scientific Name: Quercus montana
Scientific Name: Oxidendrum arboreum
Scientific Name: Pinus virginiana
Scientific Name: Pinus rigida
Scientific Name: Acer spicatum
Determining Distribution of Certain Species
The Sweet Buckeye is a tree that does not occur anywhere inside the glacial boundary. This may be due to trouble repopulating in the clayey, high-lime glacial tills. The Hemlock tree is also in unglaciated eastern Ohio. This is likely due to its restriction to continuously cool, moist environments, like in the bottom of deep valleys. The Rhododendrun is a plant found south of the glacial boundary. This species likely lived in the Appalachian highlands and migrated down through the pre-glacial Teays River.
The Cedar Bog that we went to is actually a fen. A fen “flushes” and a bog “clogs.” In a fen, water enters as rain and through springs. Small streams drain the fens flushing the system. The groundwater contains dissolved limestone making the water alkaline, and sedges grow in this water. The glaciers passed through the Cedar Bog area, leaving the site in the bottom of a valley. This valley is essentially a giant aquifer, which holds large volumes of cold ground water. This cold habitat allows it grow unique plant species!
My Assignments (2 plants with animal adaptations)
My assignment given during the field trip was to find two plants with animal adaptations.
Scientific name: Zanthoxylum americanum
The prickly ash is recognizable through many distinct features such as dark brown branches with prickles up to a half inch long and with a strong smell mimicking that of a lemon peel. The prickly ash has an animal adaptation because it supports the giant swallowtail caterpillar and also provides it food. However, it has thorns, and when it receives a lot of sunlight it produces furocoumarins, chemical compounds that are deemed phytophototoxicants; plants that are toxic to humans and other animals when activated by sunlight. These are adaptations that this plant has to fight off predators. (Linked here)
Scientific Name: Drosera rotundifolia
The Round-Leaf Sundew is a small plant that was found on the ground of the Cedar Bog. They are recognizable by red hairs, arranged at the base of the plant in a rosette. This plant is carnivorous and feeds on insects. To attract these insects it has an adaptation of glistening drops of mucilage, loaded with a sugary substance, covering its leaves.
Overall, this was a great trip where we got to learn about many different types of plants!