October 8, 2013

Unusual Habitat, Unusual Plants

August and September are good times to visit Ohio's fens, rather hidden spots that host an abundance of interesting plants. In fen habitats grow plants that occur in very few other places in Ohio. Just as significant is the fact that fens usually have few or no invasive plants, because they just can't tolerate the specialized fen conditions.

So what is a fen? Basically, it is an alkaline wetland through which water flows from springs and seeps. In contrast, bogs are generally acidic, contain sphagnum moss, and the groundwater level or water table provides the wet conditions. Both types of wetlands arise from the underlying geology, with fens generally occurring over limestone bedrock. Due to the cold water in fens, peak flowering activity usually does not occur until August and September  when flowering plants begin to fade from other habitats. In Ohio, Cedar Bog is the best known fen, but there are other, smaller fens scattered around the state.

Although some fens such as Cedar Bog are easy to access, others are "you have have someone tell you where to go" kinds of places--there are no formal trails, boardwalks, or other visitor facilities, which just adds to the adventure. The following photos illustrate some highlights from a few of Ohio's fens:

In the foreground is a thick area of Ohio Goldenrod (Oligoneuron ohioense), a bright yellow, flat-topped plant that thrives in wet meadows and moist sunny sites. Here is a "glamour shot" of Ohio Goldenrod, showing its big flower cluster and small, upward pointing leaves:

In the first picture, the plants beyond the goldenrod that have a white flower stalk are called Canada Burnet (Sanguisorba canadensis). This is by far the biggest population of this wetland plant that I've ever seen! Here is a closeup complete with an eager pollinator:

Getting deeper into the fen, particularly into the area dominated by the Canada Burnet, revealed some smaller plants that are absolutely stunning. Here is a tantalizing hint at what is thriving in this fen:

That purple flower is the primary reason we wanted to explore the fen that we visited most recently. It is a plant that is very rare in Ohio because of its specific habitat requirements. It is called Lesser Fringed Gentian (Gentianopsis virgata) and there were literally hundreds of them in bloom, hiding a bit in the taller vegetation. Here is this plant in all its glory:

In my previous post, I had a photo of its cousin, the Greater Fringed Gentian, which paradoxically has a smaller flower but more fringe. I'll leave it up to others to decide which is prettier, but here is a closer picture of the Lesser:

Another much sought-after plant was also in full bloom, the diminutive but lovely Nodding Ladies Tresses orchid (Spiranthes cernua):

We saw many individuals and each one was more perfect than the one before. Take a look at this closeup of the tiny flowers--the petal tissue looks almost crystalline:

An interesting feature of one fen was a small "marl meadow" where water was clearly flowing from springs and seeps. 

Near the outlet of the meadow a population of Grass of Parnassus (Parnassia glauca) was thriving:

It is a typical fen species and so beautiful with its circle of stamens and the lines on the petals. 

We also spotted a few plants of Purple False Foxglove (Agalinus purpurea). These lovely pink-purple tubular blooms are certainly reminscent of the cultivated foxgloves:

Note the lines of dots in the throat of each flower. Those are thought to be "guides" for the insect pollinators to get into the plant to obtain nectar and to rub onto the pollen-bearing structures. Apparently they work pretty well!

Some very interesting insects inhabit fens--here are just a few. This is the smallest dragonfly in North America, called the Elfin Skimmer. They are a little over an inch in size, and the female, on the right, almost looks like a bee when it flies.

Check out this next dragonfly--on the other end of the size scale is this Clamp-tipped Emerald. Watching this critter fly was just mesmerizing; when the sun caught the eyes just right it almost looked like a laser pointer! The picture doesn't really do its brilliance justice, but we were glad it stayed still long enough so that we could attempt a decent shot!

Our expectations were more than satisfied by our fen visits, and we saw some things that were unexpected--the hallmark of a good adventure. Since Halloween is approaching, I'll leave you with a photo of a very creepy looking insect that we saw. This is an Ambush Bug, most likely in the genus Phymata

Fortunately it is less than 1/2 inch long! Ambush bugs lie in wait on plants, usually quite well camouflaged, until another insect happens by that is hoping to grab a bit of nectar. Quick as a flash, the ambush bug uses those enlarged forelegs and scary claws to capture its prey. If all goes well for the ambush bug, it gets a good meal for its effort. Head on over to Jim McCormac's Ohio Birds and Biodiversity Blog for some more ambush bug photos. As Jim says, if you ever get reincarnated, try not to come back as an insect--it is not an easy life.

Anyway, we've had a great time exploring Ohio's fens!


  1. I love the very idea of a fen and I have a dim literary memory of a book that talks about fens. Your photography is amazing as always -- oh, that wild-eyed dragonfly and the ambush bug, and all the beautiful flowers.