Tuesday, March 03, 2009

Polytrichum....sp.


During winter months throughout the Ozark Highlands on north facing slopes, in cool, moist hollows, in more mesic sites with ever-elegant white oaks, and certainly in the rare bands of true forest of the region, richly-hued mosses punctuate the otherwise bare, chert-chocked soils. Primeval, ancient plants, mosses belong to a group of non-vascular (lacking xylem and phloem) plants called bryophytes (Division Bryophyta). While many folks are aware that vascular plant diversity is extremely high in the Ozarks (900 species recorded from a single state park in the St. Francois Mountains), lesser known may be the status of our bryophyte diversity. Include little seepy areas all over the carbonate rock-dominated Ozarks and you end up with an enormous list like the latest report to come across my desk: 90 pages of bryophytes identified in a single season's survey in my personal favorite 5,000 acres of fire-mediated woodlands in the Niangua Basin.

It's instinctual to crouch down in moist areas to feel mosses, to rub the palms of my hands over them, to finger the spore-producing structures as they spring back with the gentlest touch. Mossy areas of Ozark woodlands are usually primeval places, rich with ferns, salamanders hunkered down under rocks, spring ephemeral wildflowers, morels. While they represent a remarkably primitive life form, the natural history of mosses is--to me and not to you, probably--complex. In fact, at this point in my early education of bryophytes, were I to explain how they reproduce, hold water, and spread their colonies, I'd have to use about ten words I'd have to define parenthetically. I'm utterly fascinated by mosses, but I don't know my mosses. I photograph them repeatedly, but can only sometimes, rarely key them to genus. I can pick out a Polytrichum, a Thuidium, some Sphagnum, mainly because I use these in my dart frog tanks.

It took me a while to understand fern biology and to learn my Missouri ferns (though still looking forward to Pilularia americana in Dent Co.!). In the process, I learned wonderful new vocabulary words. (Months ago, I asked my colleague to illustrate my favorite fern for me: Woodsia obtusa. We had a hard time finding a good, live specimen for him to work from, so he chuckled at the challenge and offered, "I could just illustrate the indusia breaking open while attached to a Taco Bell cup in a sewer, piled up in a batch of maple leaves. Or just the sporangia. Yes, an illustration of your favorite fern's sporangia. Or the sporangia attached to a Canada goose's foot while flying over a golf course." We laughed at the promise of illustrations, though only several years ago I would have offered a blank stare: indusia? sporangia? Likewise a math joke heard earlier tonight in the kitchen while making Thai food: "What's purple and commutes? An abelian grape.")

Ferns, like mosses, recall grand, untrammelled places like certain parts of Oregon, New Zealand (where the largest Polytrichium moss exists), Maine. In the Ozarks, mesic woodlands possess a wide range of mosses and ferns; but if the woodlands are dominated by mosses and certain ferns, places where ground flora tends to be depauperate or characterized by Carex pennsylvanica and little else, these two groups of plants may indicate past grazing pressures. As livestock decimated the rest of the herbaceous layer, they left behind mosses, ferns and a handful of sedges. But in the right context, in ancient sinkholes, creekbanks, on dolomite ledges, in mesic conditions, moss and fern diversity is very high throughout the Ozark Highlands.

Unfortunately, there are only a few non-vascular plant experts in Missouri I can pester for tutorials. The leading scholar, the bryologist extraordinaire, Nels Holmberg is a brilliant botanist and a gentle, patient man (who owns border collies and sheep), not at all afraid of sharing his knowledge or stomping through wooly woods collecting seed ticks on his trousers, mosses and liverworts in his plant press. If I wasn't embarrassed by my lack of knowledge, I'd send him all of my moss pictures and ask him for identification help. (He'd likely sit down with me and a microscope to teach me how to key them out, instructing me on morphology rather than simply giving me the answers) But instead, when it comes to mosses, I'm behaving like so many mediocre botanists in the state who offer plant lists without proper identification, plant lists full of "unknown grass," "Desmodium sp.," and "Carex sp."...plant lists that belong in the rubbish heap, really.

So before I explain moss reproduction cycles and life history, I should understand the natural history better in order that the terminology makes sense to me (and thus to readers unfamiliar with bryophytes). Bryophytes are fascinating and diverse plants.





Meanwhile, pictures taken throughout the Ozarks on various substrates, from Mississippian limestones to ancient igneous domes. One is from a sinkhole pond in Ripley Co., others from the St. Francois Knobs and Basins, a couple from the White River Hills, and one from a very rare chert glade. Of course, just as I welcome mycological identification skills, I'll accept any positive identification on these images (comma Nels or Justin/Dana). Anything other than my current documentation: a moss. Post scriptum! Thanks to Justin, Missouri's best botanist, who offers identification because he's so awesome and great. Scroll down through the comments for a key. Justin's great. His blog can be seen on the side of the screen, the writings of an engaging botanist. Brilliant guy.

8 comments:

Justin said...

Field knowledge of bryophytes is certainly lacking throughout the Midwest. I have tried on numerous occasions to collect and key them, but I always end of frustrated. I can only identify some of the more common and charasmatic species. I am going to the Missouri Botanical Garden next week to work on difficult vascular taxa and plan on spended at least two days beefing up on bryophytes.

Of your posted photos; the first one, third one and bottom right one all appear to be Polytrichum juniperinum; the second one is Sphagnum sp. (that's the best I can do); the forth one growing with Cheilanthes feei looks to be Anomodon rostratus; the third to the last looks like Weisia sp. and the last one is the young growth of Polytrichum sp. Nels could probably do better, but thats the best I can do.

Scott said...

Great photos! I wish I could help with identifications, but I'm sad to say that I've put off learning mosses, maybe more for a lack of having a good key than for lack of desire. This prompts me to look into getting a good moss book. Any suggestions?

Nathan said...

Lovely photographs, Allison. Mosses are amazing, especially when the rest of the woods lack much color and they stand out in such brilliant green hues. I love the mosses in Polish forests, overturned, at times, by wild boar looking for goodies.

beetlesinthebush said...

You have articulated beautifully something I have long felt (but could never never express with such eloquence) - frustration with recognizing diversity in a group while lacking even a basic conversational ability about them.

I wish you luck in your attempts to learn more about them - if you do, please teach this mere mortal!

my best--ted

Allison Vaughn said...

Oh, Ted, they're hard to understand. Every genus has a different natural history with all of these parts whose names I don't know if I'll ever remember. I'll get the basic botany of them soon because I like the challenge. Don't you love the mosses though? They're just spectacular.

Allison Vaughn said...

There is a good moss book by Paul Redfearn. I don't know how hard it is to find, and someone jacked the copy that belongs to the Natural History Program. That's right, your Natural History Program doesn't have a book on bryophytes on its shelf. For shame. Hence my lack of understanding of them! I think they're hard to understand, but I'm not very bright with taxonomy...

Allison Vaughn said...

Thanks, Nathan. European forest (true forest over there!) ground flora is amazing when you find it in good shape. You know, our non-native feral hogs are doing a great job at ruining our moss diversity here in the St. Francois Mountains...well, and every other aspect of natural history. I bet the Polish forests have adapted to wild boar, considering they've been part of the matrix for hundreds of years.

Allison Vaughn said...

You, Justin, are superbad. Thank you. I wonder if the sphagnum that I found at Cupola Pond is restricted to the tupelo communities in the state. I know it's not at Big Oak. I love the sphagnums. You are such an incredible botanist.