The best-smelling Fen

DSC_0041I cheerfully admit it: wetlands sometimes stink! Many is the time I have smelled an earthy, or musky, or sulfur-like odor as I walked or sloshed around a wetland. Just remember, please— such smells are normal, even beneficial. The characteristic odors are a sign of a wetland at work. In previous posts, we’ve thought about wetland chemistry, and its relationship to water movement and storage. Water carrying silts, sediments, nutrients…it enters a wetland, and is chemically transformed, as the wetland “cleans the water.” That work may not be aesthetically pleasing, however. Actually, your nose is quite attuned to smells which signal something you shouldn’t eat (like materials in a working wetland), and assign those odors as “stink,”and that’s a healthy thing too.

But at Rowley Fen, just outside the town of Rowley in Buchanan County, I was surprised to find something else entirely. Not only did the soil and water have no objectionable odor, I was actually delighted by what I smelled: a pronounced odor of mint! I looked down, and found that indeed I was walking among a thicket of mint plants!


Unlike the ferns and sedges around it, mints produce pretty little flowers with bright petals, presumably to attract insect pollinators. And oh, the aroma! The damaged stems or leaves released a pungent-yet-delightful smell of mint. The smell comes from aromatic chemicals common in the Mint Family (Lamiaceae/Labiatae). Other common characteristics are stems with sharp corners (i.e., square in cross-section) and flowers with a pronounced, and protruding, lower lip (labia means “lip”).

This particular plant is Mountain Mint, Pycnanthemum. I suspect P. virginianum although I could be convinced of P. tenuifolium if someone wants to make a case for it. A search on the internet will find useful information about propagating the plant and its value (including from a local supplier of wildflowers; no recommendation implied by the link). Notice many accounts on line about uses for the plant—food, tea, tonic, specific medicinal value. As I’ve mentioned before, plant use by humans (and cultural significance of plants) is a subject called Ethnobotany, and one I find fascinating. My students (such as those currently in my Field Botany class) enjoy learning about this, too. But I caution you: know with great certainty, the identity of a plant; use caution when considering a food or medicinal use. Even honest writers may inadvertently be passing along faulty information; or, your body may react differently than most. Be careful!

Anyway, it smelled wonderful, partly because it was a delightful surprise: most smells in the wetland are less pleasing (or, with my seasonal allergies, I don’t smell much at all…). Unexpected pleasures are often the best ones, in my experience!

DSC_0038The wetland was nestled in a little low spot, easily reached from the parking lot. A sign welcomed you and explained the basics of the ecosystem. Walking on the peat surface was fun: it had a characteristic spongy texture, riding above the groundwater. The peat mat even quakes a little, reminding me a bit of Silver Lake Fen or Becky’s Fen.

I couldn’t spend as much time at Rowley as I would’ve liked: a thunderstorm was rolling in. But I appreciated my brief visit, and would enjoy returning some time. Maybe I’ll “sniff out” some other little delights. Do you have a favorite natural smell, or place to stop and smell the…whatever? Leave a comment!


Author: Paul Weihe

Associate Professor of Biology at Central College, traditional author (Textbook of Limnology, Cole & Weihe, 5th ed.; Waveland Press), and now...blogger!

4 thoughts on “The best-smelling Fen”

  1. Thank you for including the photo of the sign! Reading it brought back a memory. Sorry, it’s a long memory, but I’ll get to the reference.

    Years ago, I think in the Nineties, there was a North American prairie conference held in Ontario, where, it turned out, there are some amazing original tallgrass prairies. One of the featured field trips was a visit to Walpole Island on the edge of Lake St. Clair.

    I grew up in the Detroit area and had often visited Harsen’s Island, which is also on the edge of Lake St. Clair but on the Michigan side of the international boundary. Harsen’s Island is a developed island with lots of houses. It has some protected wetlands, but a lot of what I saw back then (I think there has been restoration work since) was just big stands of phragmites and cattails.

    But Walpole Island, right across the channel on the Canadian side, was inhabited by the Ojibwe, Potawatomi, and Odawa peoples of the Walpole Island First Nation. Our conference organizers got special permission to visit some Walpole natural areas, and we learned that they were managed with fire in traditional First Nation ways.

    We saw some amazing places, but the one I remember best took us venturing slowly out into a broad sunlit wetland where I suddenly realized I was about to step on a beautiful clump of grass of parnassus. I lifted my foot in horror and then looked around. I was surrounded by hundreds of clumps of grass of parnassus, plus many other wildflowers. It was wonderful.

    What reminded me was seeing “grass of parnassus” on the Rowley Fen sign. If Rowley Fen has grass of parnassus, I already know it’s a special wetland.

    Liked by 1 person

    1. Wow, that’s an amazing memory…thanks for sharing it!
      Small world, too. I was born in Detroit, grew up in the area. Never thought I’d end up wandering around Iowa, but life is funny that way!


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: