Shale Barren Shenanigans

The central Appalachians contain a very unique ecosystem- the shale barrens. Here, in the rain shadow of the Appalachian mountains, dryer conditions combined with steep, shallow, extremely rocky soils create desertlike conditions on certain slopes- the shale barrens.

Shale Barrens midslope
Midslope of a Shale Barren

This bizarre ecosystem contains a ridiculously high number of endemic species, including at least eight plant species and a butterfly (Grizzled Skipper) only found in and around Central Appalachian shale barrens. One of the stranger ones, and one that’s been on my bucket list for years, is Eriogonum allenii, the Shale Barrens Buckwheat. The vast majority of Eriogonums are native to the Southwestern United States, but this one occurs quite off by itself along the Virginia-West Virginia border.

Eriogonum allenii
Shale Barrens Buckwheat (Eriogonum allenii)

The large, hairy leaves stand out on the sparse rocky slopes, as do the chartreuse flowers.

Eriogonum allenii leaves
Basal leaves of Eriogonum allenii

Eriogonum allenii is something of a mystery to botanists, being so far northeast of this genus’ typical range in the mountains and deserts of the Southwest. It is assumed that an ancestral Eriogonum somehow ended up here before conditions became wetter, but honestly who knows. For some reason, it was picked up by garden centers for a year, and I saw my first ones surviving happily in a pot at the garden center I used to work at. Ever since, I’ve wanted to find the species in its natural habitat.

Shale Barrens top
View from the top of a shale barren

Having climbed to the top of the hill and seen Eriogonum allenii, I figured I’d look around for some of the other local oddities after I admired the view.

Lespedeza violacea
Violet Bush Clover (Lespedeza violacea)

Lespedeza violacea was an old friend at this point, having shown up in that summer’s survey work many times. Still, it was nice to see something in flower besides the Eriogonums.

Antennaria virginica
Shale Barrens Pussytoes (Antennaria virginica)

Many of the plants on the barrens grew low to the ground, forming moisture-holding rosettes and covering their leaves in dense hairs for added protection. Such was the case with what I presume to be Antennaria virginica, the Shale Barren Pussytoes, another endemic and fairly common here. This plant is named for its “cat’s paw” like flower clusters.

Draba racemossisima
Rocktwist (Draba ramosissima)

Another little hairy rosette is Rocktwist (Draba ramosissima), a spring-blooming mustard family member restricted mostly to calcerous cliffs in the central and southern Appalacians and foothills. Most barrens plants are spring-blooming, taking advantage of the more consistent moisture at that time.

Allium oxyphilum
Lilydale Onion (Allium oxyphilum)

However, not all plants bloom in the spring here, and one of the more confusing ones had an individual left in full bloom. Lilydale Onion was for years considered a member of the Nodding Onion species (Allium cernuum) but of late taxonomists have agreed that for various morphological and genetic reasons it is in fact its own, extremely rare species. One of the notable features of Allium oxyphilum is its tendency to bloom a month later than Allium cernuum (August to early September, as this one was doing), as well as its preferred habitat of shale barrens. Allium oxyphilum is quite rare, and little studied since the recent split. It seems to be only found along the Virginia/West Virginia border in shale barrens.

Paronychia montana
Mountain Nailwort (Paronychia montana)

I have an excessive fondness for tiny and rare flowers. Paronychia montana fits the bill. It’s virtually invisible to a non-botanist, and its tiny green flowers are hard even for a botanist to see right away. Yet again, this plant loves Central Appalachian shale barrens and is rare away from them, though not impossible to find in other dry areas nearby.

Sedum Glaucophylum
Sedum glaucophyllum

I was coming downslope, and below an Eastern Redcedar found a healthy stand of Sedum glaucophyllum, a Central Appalachian speciality not restricted to shale barrens, but typically found only on dry rocky hillsides. The succulent leaves store up water in this desertlike environment.

Solidago harrisii
Shale Barrens Goldenrod (Solidago harrisii or Solidago arguta var harrisii)

Another taxonomic controversy of the shale barrens is Solidago harrisii, the cleverly named Shale Barrens Goldenrod. Sensing a pattern? Many taxonomists keep this as a variety of Solidago arguta. I don’t particularly care, but having seen other varieties of Solidago arguta, it definitely strikes me as something unique. A fall bloomer, Solidago harrisii was just starting up in early September, the time of my trip.

Shale Barrens upper slope
Steep slopes of a shale barren

Large gaps between plants began to be the norm as I worked my way gingerly downslope.

Virginia Pine
Virginia Pine (Pinus virginiana)

Virginia Pine is the dominant tree in these dry areas, where few other trees dare to tread. I noted a bug hiding in the needles and grabbed it.

Tetyra bipunctata
Shieldbacked Pine Seed Bug (Tetrya bipunctata)

This unusual shield bug is a specialist of pine trees and was a new find for me, as well as being one of the few animals willing to brave the hot, dry conditions.

Selaginella rupestris
Rock Spikemoss (Selaginella rupestris)

Most of the way downslope, the barrens gave away to bare bedrock. In crevices Rock Spikemoss, a vascular plant despite its name, grew shriveled up- it uncurls when there is moisture.

Clematis albicoma
White-hared Leatherflower (Clematis albicoma)

A shaded crevice provided refuge for the last of the shale barrens plants I found that day- Clematis albicoma, the White-haired Leatherflower. Clematis may be a familiar garden vine, but across much of the Southeast in dry barrens and glades, nine species of upright, shrubby, bell-flowered clematis eke out a living. Most of these “leatherflowers” are rare and range-restricted. Three of them are limited to western Virginia’s shale glades, and the fourth, C. albicoma, is found only in the shale barrens of West Virginia and Virginia.

Now, like the Clematis, I too desired some shade, and a nearby creek provided excellent shade, as well as two other Central Appalachian dwellers.

Torrent Sucker
Torrent Sucker (Thoburnia rhothoeca)

Torrent Suckers are a species of sucker (in the same order as minnows, goldfish etc.) They are well suited to fast-flowing riffles and rapids along mountain streams, taking up a niche held by some species of darters in other drainages. Like many of the shale barren endemic plants, Torrent Suckers are only found in Virginia and West Virginia.

Blue Ridge Sculpin
Blue Ridge Sculpin (Cottus caeruleomentum)

Finally, a Blue Ridge Sculpin, found only in a few Atlantic river drainages, hid on the bottom of the river. Like the suckers, they too stay low to the ground, sticking out between rocks to avoid being washed away in the fast currents of mountain streams. The dip in the stream was refreshing after the hot hike on the shale barren. I sadly had to drag myself away from the delightful area, and back towards home, for I had “miles and miles to go before I sleep”.

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