Final Blog

In my second season at the Chesapeae and Ohio Canal National Historical Park I found several new occurrences of RTE plant species and recorded three new species for the canal.  That puts the total number of new rare and endangered plant species I discovered while doing survey work over the last two years at seven.  These seven species were Gymnocladus dioicus, Trichostema brachiatum, Heracleum maximum, Ribes americanum, Panax quinquefolius, Aristolochia macrophylla and Liparis liliifolia.  The Ribes americanum discovery was the first time that plant had been seen in Maryland for over 100 years and is listed as extirpated.

I greatly expanded my knowledge of riverine habitats and their associated disturbances. I surveyed several areas of high quality limestone habitat and floodplain forests.  I learned valuable lessons in regards to managing a large database of rare plant records and was introduced to the process of writing and submitting a scientific paper for publication.  I met a lot of nice people working for the National Park Service and saw some of the challenges facing the agency.

I had the opportunity to participate in a sedge workshop in Syracuse, New York led by Tony Reznicek.  Tony is a very nice man and an extraordinary botanist.  Getting the chance to meet him was one of the highlights of my internship.

Tony Reznicek discussing sedge things on a field trip in New York.

I also wanted to mention that I stumbled upon a book called Wild Flowers of the Alleghanies by Joseph E. Harned.  This is a very interesting book by one of the less celebrated botanists of Maryland.  In the book I found an autographed photo of the author.  I don’t know how or why it got there but it was a pleasant surprise.  The excerpt on Aristolochia macrophylla I included in my previous post was from this book.  It doesn’t have any keys but some of the species descriptions include interesting comments.  I really dig this kind of thing and thought I’d share.

I love old botany books and this was a fine addition to my collection.

This job over the past two seasons has been one of my favorite seasonal positions.  I’d like to thank the park staff and the Chicago Botanic Garden for making this opportunity possible.

July 2017

While doing some research on the land-use history of one section of the park I came across some interesting information and photos.  Our park keeps physical documents of the land acquisition transactions that took place when tracts were being bought and added to the canal boundary.  Among these records were appraisals.  These appraisals included timber values and documentation of all structures on a tract of land.  The timber appraisals even listed the number of trees over 14” dbh and the species, although it wasn’t always specific for some groups like maples and ash.  You could get a rough idea of the character of the forest at that time.  Pictures of structures were also included.  They were meant to document the structure only but some photos showed the surrounding landscape.  These photos and maps helped show the extent of disturbance during that time period.

One of the seasonal/recreational structures found along the Potomac River. This photo is from the 1970s. When the National Park Service obtained these properties most of these structures were removed.

I assisted a contract botanist with his survey on canal lands this month.  I always find it interesting to talk with botanists in the private sector about their experiences.  We had a successful couple of days surveying and found 6 new rare plant records for that portion of the canal.

View from atop one of the bluffs that was surveyed.

One of the plants we found was a new species for the park.  Aristolochia macrophylla is listed as imperiled (S2) for the state of Maryland.  The synonym for it is Isotrema macrophyllum.  Previous records for this plant in Maryland are from Garrett and Allegany counties.  This plant was found in Washington County which borders Allegany County.  After reading up on this plant I found out that is or was planted widely as an ornamental.  This information and the fact that the vines I found were near a lock and next to a pile of gravel, lead me to believe that this occurrence is probably an escaped population.   I ran into a similar situation with Kentucky Coffeetree (Gymnocladus dioicus) which is a state-listed tree but widely planted in the area.  I will include all this information in my records and still map the occurrence for the park’s database.  I also plan to reach out to the state botanist to get his opinion.

Aristolochia macrophylla (Pipvine)

Aristolochia macrophylla (Pipevine) climbing up a Sycamore tree.

Here’s an excerpt from a old plant guide I purchased this season that the interesting pollination strategy of this vine.

I didn’t get to catch this one in flower but I wish I did after reading this.

Lastly, I found this cool looking Sphinx Moth (Eumorpha pandorus) on a Hackberry (Celtis occidnetalis) leaf along the canal towpath.  I also found an early-instar Giant Swallowtail (Papilio cresphontes) caterpillar on the leaf of the state-listed (MD) shrub, Hop tree (Ptelea trifoliata).   The Giant Swallowtail is a state-listed butterfly in Maryland and I was glad to finally sight one.  The caterpillar’s strategy of disguising itself as bird poop is really interesting in my opinion.

Sphinx Moth (Eumorpha pandorus)

Giant Swallowtail (Papilio cresphontes) caterpillar

Those are the highlights from July.

June 2017

The last week of June has been glorious in terms of weather but the rest was very hot and humid.  I had the opportunity to participate in a few non-plant related activities recently.  I assisted with a breeding bird survey and tagged along with the park’s geologist intern to visit some caves and poke around for fossils.  I still got out to do some plant surveying though.

One plant that occasionally gets overlooked by some is Polygonatum pubescens (Hairy Soloman’s Seal).  It grows alongside and appears very similar to another species within this genus, Polygonatum biflorum (Soloman’s Seal).   Fortunately, once you are aware of the two species they are easily distinguished even without flowers.  The leaves of Polygonatum pubescens have lines of hairs on their underside while Polygonatum biflorum’s leaves are glabrous throughout.

Polygonatum pubescens (Hairy Soloman’s Seal)

Polygonatum pubescens (Hairy Soloman’s Seal) A close-up of the leaf underside showing the rows of hairs along the veins. Folding it over the finger like this seems to be the best way to see them. A hand lens is not required to see them.

I feel obligated to mention that distinguishing the genus of Polygonatum in a vegetative state from other similar genera took me several seasons to learn.  Some of the genera that can look similar to Polygonatum in the eastern U.S. are Maianthemum spp., Uvularia spp., Prosartes spp., and Streptopus spp.  It’s also worth mentioning that the synonym for Maianthemum is Smilacina while the synonym for Prosartes is Disporum.   Distinguishing these genera when in flower is a lot simpler.  However, typically Polygonatum spp. can be separated from Maiantheum racemosum by leaf margin characters and these two genera I just mentioned can be separated from Prosartes spp. and Streptopus spp. by whether or not their stalks are forked.  I have never personally seen Streptopus spp. in the field.

I also found Ruellia strepens (Limestone Wild Petunia) in flower this month and realized just how inconspicuous it is when it is not in flower.  The common name of this plant is slightly misleading.  Although it may grow predominately in limestone areas it is not limited to them.  One of the populations I found was around the Potomac Gorge area in a floodplain forest.  This species is listed in Maryland as a S2S3.

Ruellia strepens (Limestone Wild Petunia)

Ruellia strepens (Limestone Wild Petunia) The calyx lobe width is an important character in distinguishing species within this genus.

Not far from where I found the Ruellia I checked out a rocky river outcrop along the Potomac and found two other state listed species.  One of those species was Trachelospermum difforme (Climbing Dogbane) which I discussed in a blog entry last season and is an S1 (Endangered) species.  The other was Hibiscus laevis (Halberdleaf Rosemallow) an S3 (Watchlist) plant.  I guess the interesting thing about the photos I took is that they show each plant in an immature state.

I should note as I stated in my previous entry that leaf shape for climbing dogbane is listed as “variable” in the manuals.  To my eyes the young leaf grow was linear and narrow with more vigorous/older stems showing the orbicular and wider leaf shape I was used to seeing.  With that said I can’t be certain if these young “narrow leaves” will retain their shape as they grow or morph into the orbicular form.  I also can’t be certain whether or not this narrow growth is a result of physical damage to the stems.  The stems are exposed to potential damage from flooding and visitor trampling.  Additionally, in my previous post I neglected to mention that some species descriptions for climbing dogbane state that milky sap is not always detected when its tissue is broken.  As with all populations I have encountered on the Potomac, these plants did have milky sap.

Trachelospermum difforme (Climbing Dogbane)

Trachelospermum difforme (Climbing Dogbane) The population was in fierce competition with Campsis radicans, Toxicodendron radicans, and the non-native shrub, Ulmus pumila.

Halberdleaf Rosemallow is not especially uncommon along the Potomac River.  The pictures I took captured it at about the half way point in terms of its growth height.  The leaf shape is very distinctive.  It could be confused with Hibiscus moscheutos (Crimsoneyed Rosemallow) which can have slight lobing of the basal portions of some leaves.  Typically Halberdleaf Rosemallow holds true to its name and possesses well defined lobes throughout.  One of the interesting observations I noted from this population was the deformities in the leaves as seen in the pictures.

Hibiscus laevis (Halberdleaf Rosemallow)

Hibiscus laevis (Halberdleaf Rosemallow)

Hibiscus laevis (Halberdleaf Rosemallow) This picture shows an example of the leaf deformities I observed. This type of deformity occurred in every clump of plants though varied in abundance on each stem.

I’ve crossed the halfway point of my internship once more.  July will be a busy month because many of the G1-G3 priority species on my list are flowering in that period.   July on the Potomac is particularly exciting for me because the decrease in rainfall that usually occurs opens access to certain islands and scour bars on the river where so many interesting and rare plants grow.

May 2017

I never cease to be amazed at how different a rich forest habitat can look from spring to summer.  Rock outcrops on slopes of these areas that once stood out as clear as could be in spring are often covered in thick herbaceous level growth by this time of year.  Unfortunately in some cases this is because an invasive plant such as Garlic Mustard has reached maturity in such numbers as to obscure the ground level.  Native undergrowth in more stable areas can achieve the same effect.  I have been spending a fair amount of time surveying in cool, shaded, north-facing forests associated with limestone rock outcrops recently.  One of my priority target species, Arabis patens, occurs here.  The genus Arabis, and the Brassicaceae family in general, can be a difficult group of plants to identify.  Recent taxonomic treatments have placed some species previously found in Arabis into other genera such as Boechera, Borodinia, and Arabidopsis.  This only adds to the difficulty.

Arabis patens (Spreading Rockcress)

Arabis patens (Spreading Rockcress) This picture shows the fruit, sub-entire to entire middle cauline leaves, dentate lower cauline leaves and the smaller basal leaves. I’ve found that leaf size, shape and dentation varies among individuals.

These limestone bluff forests contain some interesting geological formations.

Jeffersonia diphylla (Twinleaf) is not a rare species in Maryland but it has caught my attention over the years because of the bad luck I’ve had trying to catch it while it is in flower.  Fortunately I was able to catch it this season as I discussed in a previous post.  I also ran into huge patches of it in May.  I have observed patches stretching for acres that have approximately 80 percent cover throughout.

Jeffersonia diphylla (Twinleaf) The seed capsule has opened and fallen over, spilling its seeds onto the ground.

Jeffersonia diphylla (Twinleaf) The seeds look like ovate popcorn kernels. The out of focus plant next to them is a Twinleaf seedling.

Some other species I’ve recently encountered in rich woods, although not necessarily in north-facing limestone associated forests, were Viola canadensis, Maianthemum racemosum and state-listed Panax quinquefolius  Panax quinquefolius (Ginseng) is a well-known plant in the Appalachian region.  Because of its commercial value it has been extensively harvested throughout its range.   This exploitation has earned it a G3G4 global ranking from NatureServe.  I find this plant’s foliage quite attractive and its presence in an area usually indicates the habitat is stable and possibly high quality.

Viola canadensis (Canada Violet) This species can reach over two feet in height. The yellow throat of the flower is a diagnostic character.

Maianthemum racemosum (False Solomon’s Seal)

Panax quinquefolius (Ginseng)

I caught another well-known plant, although for much different reasons, in flower recently.  Toxicodendron radicans (Poison Ivy) is a common vine that for whatever reason I don’t see in flower often.

Toxicodendron radicans (Poison Ivy)

Lastly, May 19th was Endangered Species Day.  I participated in a youth event held in Cumberland, Maryland that discussed rare species with groups of 4th graders.  I got a kick out of one child who attempted to explain how “Bigfoot” was a rare species.

Coleman Minney

April 2017

It has warmed up quickly in Maryland this year.  I spent a lot of time surveying the limestone bluffs along the Potomac River which has a very nice spring ephemeral display.  In my previous season working at the canal I arrived after the peak of this floral display. Twinleaf is a prime example of one these spring ephemeral species.

Jeffersonia diphylla (Twinleaf) I don’t always catch this species with flower because they last for a short period of time.

I keyed out a couple new invasive plant species as well.  The first was Thlaspi alliaceum (Garlic Pennycress).  This weed seems well established in Maryland and probably has been for a while.  It has been described as a “newly invading species” by some in states such as Ohio as recently as 2015. It occupies acres upon acres of fallow agricultural fields in the Hagerstown Valley and occasionally occurs in smaller though still dense patches along the floodplain forest of the Potomac River.  These observations lead me to believe it prefers open sun and recently disturbed soil.  I have never seen it in upland habitats.  It looks similar to some other weedy species of the Brassicaceae family.  One of the better diagnostic characters of Garlic Pennycress is the slight garlic odor it emits when the tissue is broken.  It belongs to the same tribe as Alliaria petiolate (Garlic Mustard).

Thlaspi alliaceum (Garlic Pennycress) The light green in this photo is Garlic Pennycress flowering in the thousands in a farm field close to the canal.

The other invasive species is Lamium galeobdolon (Yellow Archangel).  I found a small patch along the Potomac River in central Maryland.  The Mid-Atlantic Exotic Plant team of the National Park Service recently released an invasive plant alert for this species in the region.  I reported the location of this species to the Park Biologist for eradication.

Lamium galeobdolon (Yellow Archangel) To my knowledge this is the first time this invasive plant has been recorded in the canal boundary.

The state Natural Heritage Program botanist was nice enough to meet me in the falls line area of Maryland to review several species of Amelanchier that he had done genetic testing on several years earlier.  Amelanchier nantucketensis is one of the G1-G3 plant species that I am focusing my surveying efforts on this season.  We found it in flower and he schooled me on some of the nuances of hybridization within this genus and their morphological character overlap.

Amelanchier nantucketensis (Nantucket Serviceberry) The short and narrow petals of this species are diagnostic. Interestingly, the petals will sometimes bare pollen.

I briefly visited the shale barrens of western Maryland as well and was happy to find a few of the endemic plants that grow there in flower.

Trifolium virginicum (Kate’s Mountain Clover) Shale Barren endemic


Coleman Minney

Chesapeake and Ohio Canal National Historical Park

Final visit to the shale barrens

My internship has concluded and it was a very good experience.  I had to leave earlier than I expected, which meant I didn’t get to visit every place in the park I wanted to, but things happen.  Perhaps I will visit again.  I found over 20 new populations of state-listed plants in the canal including 4 entirely new rare species.  I also found a population of Ptilimnium nodosum (Harperella) which is a federally-endangered plant.  Check out my previous entry for more details on that find.

I learned a lot about managing a large database of rare plants.  The amount of rare plant records for this park meant that I couldn’t possibly survey for all of them in one field season.  One challenge was prioritizing which plants to survey for.  I gravitated towards the shale barren habitats within the park.  I found these to be the most interesting to survey.

My last trip into the field was to survey a shale barren habitat.  I found a new population of the globally-vulnerable (G3) Trifolium virginicum.  This is one of the discoveries I was most excited about.  I can’t quite explain it but I really enjoy seeing this plant.  On this field trip I found a population with newly established clumps and one clump that had seedlings sprouting.  I was pretty excited when I saw this and considered it a fitting end to my internship experience at the Chesapeake and Ohio National Historical Park.


Trifolium virginicum. One clump of a new population I found on my last day of field surveying.












This picture shows the habit of the seed heads to hang down around the base of the plants. They blend in very well with the shale talus.



This is a closer view of the seed heads. If you look closely you can see the seedlings sprouting.


Coleman Minney

Field Botany Intern

Chesapeake and Ohio Canal National Historical Park

First air of autumn

This will be the final blog post of my internship.  One of the more interesting recent developments for me is finding Ptilimnium nodosum (Haparella) in the park in late July.  This is a federally-endangered plant in the Apiaceae (Carrot Family).  In the 2000s there was a major re-introduction effort within the canal between a professor at George Washington University and the National Park Service.   From my understanding this re-introduction was not successful at establishing new populations, but some useful knowledge was gained through the experience and seeds from it were acquired for long term preservation.  The last time a natural population was found on the main stem of the Potomac River was around 20 years ago.  I hope I am giving enough of an overview while practicing a fair amount of discretion due to the sensitive nature of this information.  I went to that location where it was last seen (a well-developed scour bar) and was surprised to find a decently-sized population in full flower.  I think one could describe this as a meta-population.


Ptilimnium nodosum. Each umbel was rarely larger than a dime.


Ptilimnium nodosum. Even in flower these plants were hard to see. They grew alongside numerous wetland graminoids such as Juncus spp.


Ptilimnium nodosum. The leaves are referred to as phyllodes (reduced leaf petioles). They are hollow and segmented.











As I mentioned in a previous entry, the Potomac at this time of year is usually at its lowest point.  I was able to walk out into the middle of the river and could have crossed into West Virginia on the other side if I desired.


From the middle of the Potomac in late July. The green is Justicia americana (Water Willow)

Another interesting plant I ran into with the help of a lady who has voluntarily been doing plant surveys along a portion of the canal for several years is the state-endangered Trachelospermum difforme (Climbing Dogbane).  Not only had I never seen this plant before this summer, but I had never even heard of it.  This plant is of particular interest to me because it resembles Japanese Honeysuckle morphologically and in growth habit.  As I discussed in a previous entry, the canal is very interested in developing a robust volunteer Weed Warrior program.  Part of my responsibilities involve educating these Weed Warriors about native look-alikes, especially state-listed species.  I must admit that this one is tricky at first and would especially be difficult to less experienced eyes.  Fortunately once you are aware of the plant, it is easily distinguished from Japanese Honeysuckle by its milky sap when leaves are present.  On the other hand I can imagine some difficulties for volunteers because the two can grow intermingled in each other.  This would be particularly hazardous if they are growing together, it’s late in the season and Japanese Honeysuckle is still green while Climbing Dogbane has gone dormant.  The “hazard” being that dormant Climbing Dogbane is mechanically treated by someone thinking it is part of a honeysuckle clump.


Trachelospermum difforme. The milky sap I mentioned earlier.


Trachelospermum difforme. In flower. The manuals state that leaf shape is variable. Some of the leaves were quite oribicular with an acuminate tip. They resembled Oriental Bittersweet leaves to my eyes, though that vine has alternate leaves.

IMG_9143 (2)

Trachelospermum difforme vs. Lonicera japonica (Japanese Honeysuckle). In my hand is Japanese Honeysuckle. As you can see the two grow alongside each other and can easily be confused as one species.

I went through the photos I took over the season and thought I would include some of the more interesting ones here for fun.

Io Moth caterpillar on Baptisia australis leaf

Automeris io (Io Moth) caterpillar on the state-listed Baptisia australis. Will sting you.

Eriocampa juglandis (Butternut Woollyworm) on state-listed Juglans cinerea (Butternut) leaf.

My internship still has a few weeks left but I feel the season waning.  The asters will have their time and fall will be here soon. Cheers to a successful field season.



Coleman Minney

Field Botany Intern

Chesapeake and Ohio Canal NHP

July in Maryland

There has been a prolonged stretch of hot, humid days here in Maryland.  This weather can make field work unpleasant at times but there is a silver lining.  The decrease in the amount of rain, which is normal for this time of year, allows the Potomac River to drop to lower levels.  This drop has implications for the rare plant survey work I am tasked with for my internship.  River scour habitats were a new concept to me when I first got here and read about them.  The idea of grassland maintained by erosion from flood waters on river islands and river edge habitats was something I never really thought about.  With the drop in water levels on the Potomac, surveying these river habitats has gone to the forefront in my mind.  In particular, the historical records of the federally-endangered Haperella (Ptilimnium nodosum) within the canal have caught my interest.  The last time this plant was seen on the Potomac was around 20 years ago.  Even though I know the chances of finding it are remote, I still can’t help but hold out a little hope.  This plant has a habit of popping up in random river scour bars one year and disappearing the next.  From the little exposure I have to these scour bars it seems apparent that the invasive plant Japanese Knotweed (among several other invasives) also thrives in this disturbed soil.  One of the harder parts of my internship is seeing situations where rare plants are under assault from invasives and knowing how best to contribute to dealing with the problem in a meaningful way in light of the limited time I will be here.


Looking upstream on the Potomac in western Maryland. The plant at the bottom of the photo is Water Willow (Justicia americana) which is very fond of growing on the edges of these scour bars.

The development of a Weed Warrior program was also one of the tasks of my internship.  Another intern and I will be giving a presentation on several invasive plants commonly found in the canal as well as control methods and native look-alikes for each.  I read a statistic in a published paper that stated 33% of the flora of the Mid-Atlantic region is considered non-native to the region or North America.  I was surprised by that number honestly.  It really underlines the importance of efforts like this for the National Park Service moving forward.  It also poses some difficulties in prioritizing how to develop a program such as this with limited time and resources to train volunteers.

This experience will no doubt be valuable to me as a person that wants to be a nature preserve manager one day.  The part I am looking forward to most is meeting one on one with the individuals afterwards and learning the challenges of maintaining a volunteer-led invasive control effort.  I also hope to learn how to tailor future educational exercises for volunteers interested in invasive removal as well as knowing who these people are and why they chose to volunteer in this particular way.

I haven’t done as much botanical surveying since my last post.  One reason for this is because I participated in a wetland plant identification course at the National Conservation Training Center in West Virginia last week.  This was a great experience.  Of the three instructors for the course, one was an author for Flora of North America and another had a major hand in developing the wetland indicator codes assigned by the USDA.  He also founded a herbarium.  Needless to say it was great being around so many knowledgeable botanists.  It was also nice talking to the other students in the class, many with permanent federal jobs, who had some helpful advice about seasonal work and graduate schools.

On one of the few trips I made into the field recently I snapped a couple interesting photos.


Purple Cliffbrake (Pellaea atropurpurea) This cool looking fern was growing in the masonry walls of one of the canal locks.


Common Water Snake. When I stumbled upon this snake I thought for sure it was a Copperhead. However, after seeing the rounded pupils of the eyes I knew it was not vemonous.

Coleman Minney

Field Botany Intern

Chesapeake and Ohio National Historical Park




Mid-summer Update

It’s the mid-point of my internship here in Maryland.  So far the experience has been fulfilling.  The extent of the Chesapeake and Ohio Canal means that there is always some place new to explore.  I wanted to highlight some of the new rare plant records I found since my last post.

It seems that many botanists hold high regard for the orchid genus no matter where you are.  They are picky plants and that makes finding them, especially in flower, a real treat.  I was surveying along the top of a limestone bluff on the Potomac River when I found the following.

Liparis liliifolia, Twayblade

This is a new species for the canal and is listed as threatened in Maryland.  This type of orchid is called a Twayblade and its flower structure is quite intricate.

Earlier this month a park visitor reported a possible Heracleum mantegazzianum (Giant Hogweed) sighting.  This invasive can be dangerous to humans if they come into contact with foliage or the sap of the plant.  When I went to investigate the sighting I discovered that it was the relatively smaller native Cow Parsnip of the same genus.  I put my hat in the picture for scale.  Cow Parsnip is a plant of impressive proportions.  It is actually a “watchlisted” species in Maryland so I documented the location and number of plants in this particular population.  The population stretched for about a quarter mile along the towpath of the canal.  Interestingly all the plants, which totaled around 500, were within 10 meters of the towpath.  Because of its stature I thought it was odd that it had not been recorded within the canal before this year.

Heracleum maximum, Cow Parsnip

Not far from the Cow Parsnip I located another state listed plant, Gymnocladus dioicus or Kentucky coffeetree.  The population consisted of two saplings along a road.  Because a town was nearby and this species is planted occasionally as an ornamental, I do not believe these two saplings are part of natural population.  This is one of the challenges of working in a park with a lot of urban areas along its boundary.  Of course I would rather see native plants being planted as ornamentals rather than non-native ones.  On a side note, the largest Kentucky coffeetree in the nation is located in Hagerstown, Maryland, where the park headquarters is.

Gymnocladus dioicus, Kentucky coffeetree

And finally, I found a new population of Polygala polygama on the margin of a shale barren in western Maryland.  There were over 50 clumps of this state-listed Milkwort growing directly under a power line in full sun.  It’s interesting how man made disturbance can sometimes be beneficial to conservative plants like this one.  It is obviously benefiting from the open habitat created from the power company’s efforts to keep the area under the power lines free of shrubs.  It is also interesting to note that along the same power line a little farther down, invasive plants dominate that ground cover.

Polygala polygama, Racemed Milkwort

This week I visited the Paw Paw Tunnel.  This tunnel is locally famous because of the engineering effort it took to construct it.  The tunnel is almost a mile long, straight through a mountain.  It was a strange experience to walk through it and imagine working as a laborer during its construction.

Paw Paw Tunnel, northern entrance


Coleman Minney, Field Botany Intern

Chesapeake and Ohio National Historical Park