This page focuses on plants fitting particular themes and taxonomic categories: a field botany scavenger hunt!

As a side note, I can assure the reader that the mosquito population at the Olentangy Wetlands is thriving.

Part 1: Discovering Plants That Display Specific Traits


Grasses and Sedges

Grass: Phalaris arundinacea, Reed Canary Grass. This species is native to North America and commonly forms dense monocultural stands along waterways. The stem is round, not angular, and the sheath of each leaf is overlapping, not fused; these features can help distinguish grasses from sedges.

I wasn’t able to recognize any plants as sedges during my survey of the wetlands, but that doesn’t mean they aren’t there! According to Andrew Gibson of ODNR, Ohio has over 100 species of sedges, so there is definitely more botanizing work to be done on that front. You can click through to his page for a “Showcase on Sedges”.


Invasive Plants

Bittersweet nightshade, Solanum dulcamara: You may have seen this in Ohio backyards; it’s quite common. Originally from northern Eurasia (it’s not picky about habitat, so it has a huge range) it is in the same family as potatoes, tomatoes, and eggplants. Newcomb’s Wildflowers describes its habitat as “moist thickets”, which includes most of the terrestrial acreage in the Olentangy Wetlands.

Bittersweet nightshade produces poisonous berries which are nevertheless quite attractive (like tiny tomatoes) and are spread by birds, which are immune to its toxin. It’s a shame this plant is invasive, because its flowers (produced later in the year) are so cute and distinctive:

Prof. Dr. Otto Wilhelm Thomé ”Flora von Deutschland, Österreich und der Schweiz” 1885, Gera, Germany. Permission granted to use under GFDL by Kurt Stueber.


Amur honeysuckle, Lonicera maackii: As indicated by its common name, this species’ native range is the area around the Amur River in northwestern China, Mongolia, and southern Russia. It is one of our most pernicious invasive plants. Control methods include burning and cutting, but the plant grows back extremely quickly (in fact, it’s been used as a hedge plant) and usually requires a sustained, long-term effort to eliminate completely. The most effective strategy in my experience is cutting to the root and direct application of glyphosate (the active ingredient in Round-up). Left to grow, Amur honeysuckle forms dense monocultural thickets.

This photo illustrates the devastating effect Amur honeysuckle has on native forest-floor plants like Solomon’s seal, wild ginger, jewelweed and others. They are completely gone, shaded out by the honeysuckle layer. Consequently, erosion from flood events is increased.


Life Spans

Annual: Only living one year, in which the plant must grow from seed and then make its own seed to complete the life cycle. Below: Impatiens capensis, common jewelweed.

The smaller individuals are unlikely to catch up at this rate.

Perennial: Living for many years (for some trees, centuries), and reproducing many times throughout its life.

Monocarpic perennial: Can live for many years, but will only reproduce once in its life and usually die soon afterward. Many crops are monocarpic.

Biennial: Having a two-year lifespan, with the first year devoted to growth and the second year to reproduction. Queen Anne’s Lace (Daucus carota), below, is a biennial.


Lime- and acid-loving plants

The humble Redbud, Cercis canadensis, prefers limey substrate such as that found near the Wetlands Building, far from the river. I am very familiar with this plant, having grown up in southwestern Ohio where it is abundant! Its optimum soil pH is 7.5 or higher according to Judy Kilpatrick of SFGate.

Smooth Solomon’s seal, Polygonatum biflorum, is abundant on this sandy riverbank but found nowhere else in the park. Given its preference for eastern Ohio’s acidic soils (their World of Flowering Plants page says “acidic to neutral”) I was initially surprised to see it here, but you can see in the picture above that the riverbank where I found it is quite sandy. This is an interesting example of massive differences in substrate across a relatively small area!


Monocots and (eu)dicots

Yellow iris, Iris pseudacorus (non-native): Like all the other members of Liliaceae, this is a monocotyledonous plant. It is a particularly good example of some classic monocot traits: it is herbaceous, its flowers have threefold symmetry, and its leaves are long and narrow with parallel veins. Were I to take a cross-section of the stem, its tissues would be relatively undifferentiated.

It’s very easy to see the parallel veins in the sword-like leaves on this plant!


Viola striata, Cream violet: When placed next to the iris (I actually couldn’t figure out the formatting for that so you’ll have to use your imagination) the difference between these plants become more clear. This one is smaller overall but it has much broader leaves in proportion to its size, with netlike veins spreading throughout. Though it has a zygomorphic flower, when dissected that flower would show 5 petals.

The flower is a little past its prime, but it’s still identifiable!


Plant-animal interactions (seed dispersal)

The fruit of this Bristly Greenbrier, Smilax tamnoides, won’t be ready until later in the summer, but when it is it will be a beautiful bluish-black color. This prickly climbing vine is spread by raccoons, black bears, deer, and a surprisingly wide variety of birds.

Mock Strawberry, Potentilla indica, sports a brilliant red accessory fruit. You can eat it, but it doesn’t taste like much… it’s more of a survival food. The attractive color still lures in birds and small mammals, though, who apparently have lower standards.


Part 2: Mosses, Ferns, Trees & Shrubs


Two Mosses, both alike in dignity…

1: An acrocarp with broad leaves – Plagomnium cuspidatum?

This is the dominant moss underneath the wetlands viewing platform on the western side of the site, which offers near-constant shade on a substrate of slightly clayey loam. It is between a paved walking path and the kidney-shaped “experimental” wetlands whose water rises and falls with the river. When the river floods, the area in which this moss lives becomes moist, but is not submerged like much of the woodland is.

My tentative ID for this moss is based on its growth habit, the leaf shape (ovate), and the length of each individual plant, the habitat/substrate and its distribution within the state.

2: A pleurocarp with ecostate broad leaves: Entodon seductrix?

This moss was found in the wrinkles on a tree root’s bark, very close to the river. The root’s nooks and crannies have accumulated a small amount of sediment. I am not sure about the ID of this moss because I forgot to bring my hand lens with me and when I went back again I could not find the correct tree… sigh. So my ID is not informed by a super close-up look, but by growth form, general habitat and substrate, its rarity (or lack thereof), and general physiology.

Two One Ferns Horsetail

Try as I might, I couldn’t find any ferns in the wetlands… but I found a field horsetail, Equisetum arvense, which also quite a primitive plant! This is the sterile form, photosynthesizing away to provide energy for later reproductive efforts. Once it’s established in an area, this plant can be hard to remove because its rhizomatous root system can extend more than 6′ into the soil! Not bad for something just over a foot tall.


Threats to Trees 

This ash(?) tree’s leaflet has been skeletonized by hungry insects. Really the tree has so many leaflets that its overall health is not much impacted, but if too many insects (say, a plague of locusts) descended on one tree the effects could indeed be dangerous to its health.

These spots are caused by a fungus. Amongst arborists this “disease” is known as “leaf spot” or “leaf blotch”. The spots are randomly arranged because the fungus is windblown or splashed onto the leaf. There are many different fungus species that can cause leaf spots/blotches, but in Aesculus one particular species is known, and it’s even named after its host: Guignardia aesculi. According to a University of Massachusetts website, “the disease is so common on this host that its occurrence is practically guaranteed annually”. As with the insect predation above, it’s not a significant danger to the tree unless a large portion of its foliage is actually lost, which would indicate a weakened immune system stemming from some other factor.


This plant was notable because it was covered in fragrant white flowers and being heavily visited by scores of buzzing bees. They were loving it!

Unfortunately… it’s not native. Yeah, I know. I was bummed too. This is a Border Privet, Ligustrum obtusifolium, a dense shrub native to Eurasia. It’s kind of pushy here in America, shading out plants the same way Amur honeysuckle does. Its genus contains around 50 species, many traditionally used in landscaping, and is the namesake for a famous address in modern fantasy:



Lastly, we have a tree that sometimes grows as a shrub in windswept or poor conditions (according to the Peterson’s Guide to Trees and Shrubs): Eastern red cedar, Juniperus virginiana, pictured here growing near one of the isolated small ponds at the park. It seems to be doing okay, but it’s not really a towering specimen.


I hope you had fun on your own scavenger hunt as well! Don’t forget: there’s always more to see out there.