Geobotany of Ohio

Geobotany is defined as the interdisciplinary study involving both geology and botany.

If not regarded too closely Ohio can be divided into two parts. First is the Western part, which is underlain with limestone with broad areas of dolomite, a magnesium containing variety of limestone. Limestone is a rock type that is relatively nonresistant in this humid climate. Due to this after millions of  years and the erosion that ensued, this region of Ohio has been worn down to a flat landscape. The second is the Eastern region of Ohio. This region is predominantly sandstone. This rock type is relatively resistant, and underlain by shale to the West. Erosion of sandstone occurs mainly due to the water seeping down through the rock, Since the process of eroding the natural cement of sandstone is very slow, it makes the rock resistant in nature. Shale however, is less resistant and has been worn down to low plains everywhere except where it capped by sandstone. As a result this region of Ohio has deep valleys, because erosion is only successful in eroding the shale. Creating steep-sided sandstone hills or sandstone capped hills.

The  contrast in differing rock types in Western and Eastern Ohio can be contributed to the original strata  of sedimentary rocks in Ohio. The original sequence was horizontal, with a thick series of limestone layers overlain by shales. These were in turn overlain by sandstones. This turned into a form of low arch before erosion began. This arch was in part  a product of the pressures that created the Appalachian Mountains  approximately 200 million years ago. The subsequent erosion cut deepest where the arch stood highest, this exposed the oldest rocks along its crest. Which extends north-south though western Ohio. The river that contributed to majority of the limestone and sandstone was the Teays river. This river and its tributaries and contemporaries were present in Ohio for a long time, roughly 200 million years. This river continued to erode the land throughout that entire time. The rivers activities were curtailed by the advance of the glaciers of the Ice Age, this was less than a million years ago.

They were slowed by the steep-sided sandstone hills of eastern Ohio. Therefore the glacial boundary there is no farther south than the latitude of Canton.  Glacial till is one of the depositions glaciers. The deposition was of two kinds: an unsorted mixture of sand, silt, clay, and boulders, which accumulated directly by the melting of the ice, this is called till. The other was sand and gravel materials deposited by the glacial meltwater. The glaciated region of Ohio is almost entirely covered in till. The composition of till is a reflection of its geographic materials which could be bedrock or earlier glacial deposits. So, in western Ohio you will find glacial till rich in lime and clay, which is a product of the abrasion of the limestone bedrock. In eastern Ohio however, most of the till contains little lime and clay, hills of gravel are present as well.








In western Ohio the substrate is limy, clayey till. This provides a relatively impermeable soil, high in lime. So it is poorly drained and not aerated effectively. Due to this water does not soak into the soil quickly and remains on the surface. This creates a low oxygen availability during wet periods and bad drouths  during the dry spells. Plant nutrient availability here is comparatively abundant. In eastern Ohio since the sandstone bedrock is very permeable,(aeration is higher)  where it is exposed, it makes a very acidic, low nutrient substrate.

5 species of trees/shrubs that have a distribution generally limited to limestone or limey substrates

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


5 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

  1. Chinquapin Oak (Quercus muehlenbergii)
  2. Blue Ash (Fraxinus quadrangulata)
  3. White Oak (Quercus alba)
  4. Shagbark Hickory (Carya ovata)
  5. Sugar Maple (Acer saccharum)


Name 5 species of trees/shrubs that have a distribution generally limited to sandstone hill of eastern OH

  1. Chestnut oak (Quercus montana)
  2. Sourwood (Oxydendrum arboreum)
  3. Scrub pine (Pinus virginiana)
  4. Pitch pine( Pinus ridiga)
  5. Mountain maple (Acer spicatum)


Sweet buckeye is a species that grows in the unglaciated  boundary . Its restrictions are not exactly known but it might be because there are problems with repopulating within that area . Hemlock is another plant that is in the unglaciated region of eastern Ohio but it appears to reach far north of the glacial boundary unlike sweet buckeye. This might be because it seems to grow well in cool, moist environments and at the bottom of deep valleys where there is some till. So it tends to remain cool and moist because they are so deep and open to the north . A species present south of the glacial boundary is rhododendron and its distribution suggests that this species according to Drs. E. N. Transeau and John N. Wolfe, is one of several that lived in the Appalachian highlands and migrated downward through the pre-glacial Taeys River.

Monocots at the wetlands

Tall flatsedge (Cyperus eragrostis)


This Sedge is a monocot that primarily grows in wetlands, it grows from rhizomes. Has four to eight leaf-like bracts surrounding the inflorescence. With a  hairless stem that is triangular








Annual Bluegrass (Poa annua)

Has smooth leaves with boat like boat-shaped tip. Grows in wet/moist areas such as wetlands.

grows in low clumps that are 3 to 12 inches tall. The leaf blades are hairless and often yellowish green, and sometimes dark green. The the root system is fibrous.






Limestone Loving Plants

  1. Eastern Redbud (Cercis canadensis)















The Eastern Redbud has a simple leaf complexity, with alternate leaf arrangement. As seen in the picture this plant has heart shaped leaves. When in bloom this plants flowers are pink/purplish. There is a myth that the flowers of the plant turned from white to pink when Judas hung himself.

Fragrant Sumac ( Rhus aromatica)
















Fragrant Sumac has large toothed leaves, there are 3 leaves per group. If you crush the leaf it will emit a pleasant  aroma. It blooms in May-June. The fruit of the fragrant Sumac are small are hairy.


Elm (Ulmus americana)

The American Elm is often referred to as White Elm. It is a tall tree that can grow up to 80 feet tall. The leaf arrangement is alternate. Has moderate foliage. Leaf arrangement is alternate with jagged pointed leafs. The leaves are typically 4-6in long. The Elm has strong wood and is used for many agricultural purposes, like boxes, barrels, and crates.,is%20also%20used%20for%20caskets.


Blue Ash (Fraxinus quadrangulata)














The Blue Ash has opposite leaf arrangement with pinnately compound leaves also with simple leaves. The leaves can be 8-12 in long. The stem and twigs are square so it has been nice named square-stemmed ash.,bluish%20when%20exposed%20to%20air.


2 Inflorescences from Batelle Darby  

Arrowwood Viburnum ( Viburnum dentatum)

The Arrow-wood Viburnum is a perennial woody shrub. It has opposite simple leaves and bears fruit that are  berry like drupes. It blooms in May-June. The name originates from Native Americans using the shoots that developed from the roots for the shafts for their arrows.


Golden Alexander (Zizia aurea)

The Golden Alexander has leaves that are 8cm long and 5 cm wide, The leaves have serrated margins and ovate in shape. The lower leaves are twice or three times compound, with long petioles. It is most recognized by its bright yellow flowers that bloom mid May-June. Its flowers are small, about 0.3cm long. On the Golden Alexander, each flower has 5 sepals, 5 petals and 5 stamens. The cluster of flowers gather into a 8cm long flat-topped flower head, the middle flower of each compound umbel being stalk less. It is widely distributed from Quebec to Saskatoon, south to Florida and Texas. It grows in moist environments, and limestone glades.