Field Trip #2 | Emma Ohio Plants

Geobotany (part 2)

Just like there are certain trees associated with the limestone soils of northwestern Ohio, the sandstone hills of southern Ohio also have certain plants that are more abundant since they thrive in acidic soils.

Chestnut Oak (Quercus montana)

One of these such plants is Chestnut Oak. Chestnut oak is often confused with Chinquapin oak upon identification since their leaves are quite similar, however chestnut oak has dark bark and rounded teeth instead of sharp teeth and gray bark. Quercus montana grows mostly on the tops of sandstone hills.

A closeup of the simple toothed leaves of *Quercus montana* and its rounded teeth that help differentiate it from Chinquapin oak.

Sourwood (Oxydendrum arboreum)

Sourwood is also an acidiphile and was found around the edges of a small meadow at Deep Woods. The leaves in autumn will turn to a nice orangish-red and have a sour taste when eaten although be sure you’ve correctly identified this tree before consuming any leaves. Deer have also been known to consume the twigs of sourwood trees.

Here is a picture of the edible leaves of sourwood.

Eastern Hemlock (Tsuga canadensis)

Eastern hemlock is restricted to cool, moist ravines. Additionally, it’s currently being threatened by insects called hemlock woolly adelgids. The tree itself is a conifer and produces very cute little cones that are between 1/2 – 3/4 inch.

A majestic specimen of an eastern hemlock which shows its canopy cover often used by deer.

Ferns!

Ferns are amazing plants which can be distinguished by several characteristics like frond type and frond dissection. Frond type describes the spore location and ferns can either be monomorphic (spores are produced under ‘normal’ fronds), hemidimorphic (spores are produced on fertile sections of the frond and there are sterile sections that don’t produce spores), or holodimorphic (entirely separate fronds for spore production).

Frond dissection type refers how compound/divided a leaf is. An entire frond refers to a leaf that is not divided at all. A pinnate frond is divided into leaflets where you can see the rachis in between each leaflet. A pinnatifid frond looks more lobed in comparison to pinnate fronds or the rachis cannot be seen between what might look like separate leaflets. A pinnate-pinnatifid frond dissection type means that there are separate leaflets like in a pinnate frond but the leaflets are then lobed like a pinnatifid frond. A Bipinnate-Pinnatifid fern has separate leaflets that themselves have separate leaflets also known as twice compound.

First up we have polypody, a fern with a pinnatifid frond dissection type and monomorphic frond type.

Here’s a closeup of a polypody where you can clearly see that what you might initially think are leaflets are actually connected so it’s deeply lobed instead.

Next up is cinnamon fern which has a pinnate-pinnatifid dissection type and a holodimorphic frond type.

Here’s a better look at cinnamon fern and its pinnate-pinnatifid frond dissection.

Finally, we have Royal fern which is tripinnate and hemidimorphic.

Here’s a photo of the lovely royal fern which is quite large in size for a fern.

The Appalachian Gametophyte

The Appalachian gametophyte (Vittaria appalachiana) is peculiar because it is a fern which does not have any sporophytes, and instead reproduces asexually using gemmae that break off and become mature individuals. Fern gemmae are much larger than spore gemmae and instead are most-likely too heavy to be transported by wind like spore gemmae. Alternatively, it it believed that fern gemmae are dispersed by water or potentially animals over short distances. A publication by Kimmerer and Young (1995) claims that slugs have been shown to help disperse gemmae in bryophytes. The species is also not present north of the last glacial maximum which hosts suitable habitat (known by a transplant study) and does not colonize potentially suitable habitats that are nearby. This is most likely because they have limited capabilities when it comes to distance dispersal and cannot travel far. It is theorized that the Appalachian gametophyte lost its sporophyte before or during last ice age. The current wide population range was most likely a result of the time before it lost its sporophyte (the last ice age) and therefore its ability to disperse further distances.

Invasive Plants

One of the invasive plants we found at Deep Woods Preserve was non-native barberry (Berberis spp.). The two species that are not native to Ohio are Common barberry and Japanese barberry which can act as a host of black stem rust, and have been associated with higher populations of ticks, respectively (Kulhanek, A. (2020). Plant Introductions: Meet Invasive Species Common Barberry and Japanese Barberry. bygl.osu.edu/node/1726). These plants spread through the root system and have sharp thorns which make it especially difficult to remove. However, some effective tactics have been documented such as chemical treatment like herbicide and physical methods like mowing in combination with herbicides (Kulhanek, A. (2020). Plant Introductions: Meet Invasive Species Common Barberry and Japanese Barberry. bygl.osu.edu/node/1726).

Here is the aforementioned invasive barberry.

Trees in Trouble!

One of the trees in trouble that we saw on our trip was butternut also known as white walnut. This species is being threatened by butternut fungus which produces cankers that look like sunken-in areas of the tree which progress eventually to girdle and kill the tree. The fungus is spread by insects, wind, rain splash, animals, and infected firewood. While white walnut is not considered super valuable economically, it has been used to make furniture and adds to the biodiversity of natural areas. While no sure-fire cures have been found yet, there is research being done to breed genetically resistant butternuts that could then be transplanted to repopulate areas that have been wiped out by the cankers.