Shale Barren site visit

The last part of April and early May have been very rainy here in Maryland.  The spring ephemerals have done their thing and the early summer bloomers are out in force.  A lot of sedges are on the verge of being ripe as well.  The field season is well in its prime.  I’ve seen some very nice displays including the fringe trees along the Potomac Gorge not far from Washington, D.C.


Chionanthus virginicus, Fringe Tree

One particular habitat that I have visited once and hope to more in the future is the Shale Barren.  It’s an Appalachian specialty.  They occur on relatively high elevation slopes, with shale parent rock, on generally southern aspects.  The barrens are maintained by the erosion of loose rock caused by streams below that undercut them.  This creates a very hot, dry, and rocky landscape.  Several plants are endemic to these areas.  They specialize in the extreme conditions and low competition from other plants.  Most of the endemic plants of the barrens have only been described in the last 100 years.


The slight white haze in the understory is Phacelia dubia flowering in the thousands.

The picture above is what I would consider to be on the periphery of the barren.  The more rocky and less vegetated center is not seen here.  This picture does show the general habit of trees that grow here in being slightly stunted.  When I first got here I thought to myself this looks like a recently burned area.  While fire may have played a role in enlarging these barrens, they are maintained naturally by erosion.


Astragalus distortus, Bent Milkvetch. The major distribution of this one is in the central U.S. but a disjunct population is limited to the Shale Barren habitat of the Appalachians.


Trifolium virginicum, Kate’s Mountain Clover. The distinctive vegetative character for this species is the length of the leaflets in relation to their width.

The Chesapeake and Ohio Canal runs 180 river miles across the state of Maryland and contains 200 or so state-listed species within it.  Because of this I have prioritized some species based on their global rank.  My target for instance on this occasion was Trifolium virginicum.  This species is listed with a G3 rank.  That means it is considered globally vulnerable and there may be as few as 80 occurrences on the entire planet.  For this particular species, each occurrence has a small number of individuals within the population.  I was lucky enough to relocate this record and found that the population is stable.  The last time the record was updated was in 1995.  I plan on visiting more shale barrens in the future to update records for a couple other G3 species that occur here.


Viola pedata, Birdsfoot Violet. This is not a shale barren endemic but I included it to show the rocky habitat and because I liked this particular plants flower coloration.

Occasionally you will stumble upon a plant that is common but because of its stature or pure happenstance you have never seen it before.  As many times as I have been botanizing in the woods of the eastern U.S. I have never come across the following plant.  I was happy to see it in flower and add it to my photo collection.


Obolaria virginica, Pennywort. Of the Gentian Family.

Also happy 100th birthday National Park Service.  I am looking forward to the centennial celebrations this weekend at the canal including the park-wide Bioblitz.


Coleman Minney, Field Botany Intern

Chesapeake and Ohio National Historical Park

Bottomlands and bluffs on the Potomac

I’ve almost completed the first week of my internship with the Chesapeake and Ohio Canal National Historical Park.  As a botany intern I am responsible for updating plant records for all the rare and threatened flora within the parks borders.  The park runs approximately 130 miles along a narrow corridor from the mountains of western Maryland to Washington, D.C.  I’ve spent most of my time here so far getting acquainted with the rich cultural history of the canal and the friendly staff at the park.  I’m immersing myself in the many publications on the natural resources of the area that sits on four massive shelves at the park headquarters.  In particular one publication has caught my fancy and I can’t put it down.  Some of the taxonomic names are out of date but the information it holds on the specialized habitats of the state and the plants within them is invaluable.  Shale barrens and limestone bluffs are especially interesting because this is where many of the plants I’m tasked with surveying for are located.


The first few days here involved various orientation tasks and I’ve only been in the field for a couple hours.  However, in that short time I got to see an impressive display of spring ephemerals and two state listed plants.


Delphinium tricorne, Dwarf Larkspur


Dodecatheon meadia, Shooting Star


I look forward to getting into the field more and more in the coming weeks.  The towpath that runs alongside the entirety of the canal offers great access to the entire park.


Moving forward I plan to schedule my surveying with the goal of focusing on the plants that are flowering currently or will be soon.  I also am tasked with getting the parks “Weed Warrior” program up and running. While the canal has its share of rarities and beautiful habitat, it also faces challenges including a fairly healthy crop of invasive plant species.

“Death is one thing…  an end to birth is something else…”

-M.E. Soule and B.A. Wilcox

Protecting rare and threatened plants has been a passion of mine for a while but the quotation above made the hairs on the back of my neck stand up.  After reading it I felt a renewed sense of urgency for the protection of our nations endangered species. It feels good to be in a position to make a positive contribution towards that end.


Coleman Minney
Chesapeake and Ohio Canal National Historical Park
Hagerstown, Maryland