Saturday, July 30, 2011

Elfin rock ledge plants

The delightfully politically incorrect "Fat Woman's Squeeze" at Cantwell Cliffs State Park in Hocking County. I'm sure there's a story behind its naming. This narrow fissure between a massive sandstone cliff and a huge slump block that calved from the cliff's face long ago is the quickest way to get to the park's namesake cliffs.

Hocking County is the next to smallest of Ohio's 88 counties, but probably generates the most ecotourism traffic of any county. The primary reason people come is because of gorgeous scenery. I like Cantwell in part because it is somewhat off the beaten path for most visitors and isn't as heavily visited as iconic sites such as Old Man's Cave.

Once one has successfully navigated Fat Woman's Squeeze, this is the view: an enormous sandstone overhang. A waterfall cascades from the summit, varying in intensity depending on rainfall. It was just downstream of this point that I observed the tiger spiketail that I recently blogged about.

People tend to love these sorts of places to death. Hordes of visitors stumble down and gape in awe at the rock formations. Kids and adults alike scramble over every surface that it is possible to climb upon. Dogs bark. Children yell. The most disrespectful of the lot carve or spray paint their initials or other messages that no one cares about onto the rock faces. I'd visit these places more often but the constant parade of people quickly drives me crazy. Occasionally, natural selection eliminates one when they fall from the cliffs while trying to play daredevil or get a better photo.

As a consequence of all of the foot traffic, most of the highly specialized flora that inhabits sites such as Cantwell Cliffs has long been scrubbed from the landscape. The only nooks that plants hang on in are shaded moist ledges such as above. Dripping seeps keep people at bay. The rock ledge specialties that grow on these sites are interesting and in general not well known or often photographed.

One of the most spectacular, round-leaved catchfly, Silene rotundifolia, with its brilliant scarlet flowers, has nearly been eliminated at Cantwell Cliffs. In the absence of people the catchfly would abound in the dry shaded sands under the rock alcove. It's all been trampled into oblivion, and only a few scattered clumps grow high and out of reach on the cliff face.

A personal favorite is the dwarf enchanter's nightshade, Circaea alpina. If you pay attention to wildflowers, you undoubtedly know its larger brethren, the enchanter's nightshade, Circaea lutetiana, an abundant and widepread species of woodlands.

Dwarf enchanter's nightshade is far more finicky and only grows on sandy ledges of sandstone cliffs. A big plant might tower four or five inches skyward.

The flowers are miniscule; probably twenty of them could find room on a dime. A close look at their structure reveals that this plant is part of the evening primrose family (Onagraceae). Revealing the illogic of many plant names, dwarf enchanter's nightshade is unrelated to the nightshade family (Solanaceae).

Even cooler, in my eyes anyway, is the much more obscure plant known as pellitory, Parietaria pensylvanica. While the tiny snow-white blossoms of the dwarf enchanter's nightshade may occasionally catch the eye of one of the cliff-fawning touristos, they'll never notice this one. This is a true botanists' plant.

Pellitory is a frequent companion of the aforementioned nightshade, and the ledge upon which I made these photos teemed with both.

By moving in close, we see that the pellitory is in peak bloom - that's all it does. The tiny greenish flowers are located in the leaf axils and barely noticeable. Pellitory is a member of the nettle family (Urticaceae) but fear not, it is devoid of the stinging hairs that give some of the nettle species a bad rap.

It is vital to protect some of these rock shelters from uncontrolled and unregulated people traffic, or we'd lose many elfin specialties such as these plants. Fortunately, there are a number of such sites that are protected from abuse.

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2 comments:

Jana said...

Hi Jim. Fascinating! Do you ever post about the mosses and liverworts that grow on the rock ledges? They're cool. I know little to nothing about them. I hope to go on some Ohio Moss and Lichen Association forays. Are you a member?

Jim McCormac said...

Hi Jana,

I do belong to that group, but never have time to attend their forays, unfortunately. I just don't know bryophytes - mosses - that well or I'd probably post more about them as many are stunning when seen close up.