October 3, 1994
1 think the native plant folk enjoyed their annual meeting here a few weeks ago. The meeting was hosted by our local Jefferson chapter of the statewide Virginia Native Plant Society. On the first evening the group was treated to a talk and slides on shale barren flowers, given by Tim Williams, one of our best Charlottesville field botanists. Tim comes by his enthusiasm for shale barrens honestly. He learned his plant taxonomy at the MLBS with Pennsylvania botanist Carl Keener who has made shale barren flowering plants a lifetime study.
Shale barrens are almost unique to Virginia, spreading only a bit into West Virginia, NC, MD and PA. They occur on the sides of smallish mountains, one to two thousand feet, have southern exposures, i.e. they're sunny, and tend to be very steep with a loose, rocky surface of---yes---shale, siltstones and small, conglomerate rocks. They usually have a stream at the bottom. They may be right along a road cut and easy to get to although frequently hard to keep your footing on---and the one thing they're really not is BARREN. They may look it---with the loose surface that's constantly sliding down the hill, there are lots of bare spots, and with the sunny exposure, they're often very hot and dry-looking at the surface. Actually they have quite good soil, as much as 4-5" of it and are less dry than they seem---most get 30-40" of rain a year.
What shale barrens do provide is a unique habitat and sure enough, there's a group of plant that like to grow only in this habitat---called endemics which means just that, only found in one place or one kind of place. There are about 20 shale barren endemics among flowering plants and quite a few more species that are nearly endemic. These plants LIKE the hot surface, in fact they must have it, they're what are called heliophytes, [maybe some people are too!], and since such a hot surface kills many other germinating seeds and seedlings, the competition is reduced. They like acid soil, the pH of shale barrens is between 4 and 5, and they're often good at making long root systems which sprawl out under the loose and take hold somehow---they're not easy to transplant and don't want to be transplanted, they want to stay on their shale barren, and do their , best to do so. The endemic clover with its pretty cream flower and long narrow leaves may have roots up to 25 feet long.
Each barren may have only a small number of the endemic species. One of the best studied is near White Sulphur Springs, because---what did early botanists Asa Gray, Britton, and Steele do when they came on their extended vacations at the famous old Greenbrier resort hotel nearby? They botanized, of course, and were intrigued by the curious species they encountered on Kates mountain.
Tim actually prefers the shale barrens at Headwaters, V A, on 250 west, two ridges this side of Monterey because he's found the greatest number of endemics there, about a dozen, and throughout this past season he's tried to capture each one on film at the peak of its bloom, to get slides for his talk. Early in spring, there's the pretty little pink Buckley's phlox, an endemic pussy toes and a special onion. Later on, there are clematis, a figwort, a skullcap, a very handsome bindweed, a hawkweed, a wallflower only discovered in the last four years, normally a western plant, a luxurious bright yellow buckwheat, birdsfoot violet (which grows other places, too, but likes shale barrens,.~ harebells and a ,native poinsettia. There are several ferns too and some trees, not always totally restricted to shale barrens, a dwarf hackberry, shortneedle pines and chinkapin oak. One later summer bloomer ' is a large, showy evening primrose.
Tim's slides amply confIrmed the view that barren is a .misnomer, and made everyone think again about · this unique habitat. ·" And as local president Gay Bailey said in thanking Tim "...you really haven't lived botanically until you've slid out · ofa shale barren on your backside while admiring the endemics.
Written and recorded by Bess Murray for radio station, WTJU © Bess Murray, All Rights Reserved
More on the Virginia Shale Barrens from DCR
Images:
Evening primrose growing in Shale Barrens / CC BY-NC-SA 3.0
Pussytoes; courtesy of Gloria Schoenholtz;
Skullcap; courtesy of Gloria Schoenholtz
