By. Tara R. Littlefield

Earlier this year, I was working on a project surveying for rare plants and natural communities in the Big South Fork of Kentucky.  Hidden in the biologically diverse region of the Cumberland Plateau, we share this region with Tennessee, where headwater streams flow north into Kentucky and create river scour communities along the Big South Fork of the Cumberland River. The Big South Fork is by far one of my favorite places on Earth.  The diversity of species, both plants and animals, even undescribed taxon, is astounding. And the river scour communities within this region contain more globally rare plants than anywhere else in Kentucky!   This species diversity is only compounded by the complexity of the riparian communities from emergent marshes, outcrops, grasslands, shrublands and woodlands that are maintained by the wild river scour. It’s one of the few places still left in Kentucky where pre-settlement natural conditions still exist, it’s as if you are seeing a landscape that was seen by Native Americans, a true wilderness.  And this is also one of our states largest intact forest blocks. It feels ancient, diverse and wise.   

A tale of Large flowered Barbara’s Button’s

Joining me on the Cumberland Plateau river scour botanical survey team this year were Kentucky Nature Preserves botanists Heidi Braunreiter and Devin Rodgers.  This past May 2019, one of our main target species was Barbara’s buttons (Marshallia grandiflora), an elusive rare plant tucked away behind large boulders and cobble on the river scour of the Big South Fork.   Marshallia is a genus in the aster family, and all the species within this genus occur in the southeastern United States.   Marshalllia grandiflora is endemic to the Appalachians and the Cumberland Plateau, and is currently being assessed for federal listing.  It is endangered in Kentucky and Pennsylvania, and threatened in Tennessee and West Virginia, and extinct in North Carolina.  The habitat consists of diverse prairioid grasslands that occur on the river scour of several wild rivers.  Associated plants of Marshallia consist of species you would find in a prairie such as big blue stem (Andropogon gerardii), Indian grass (Sorgastrum nutans), wild blue indigo (Baptisia australis), blazing stars (Liatris microcephala), sunflowers (Helianthus giganteus, H. hirsutus, H. decapetalus), tall coreopsis (Coreopsis tripteris), st. johns worts (Hypericum sp.), Obedient plant (Physostegia virginiana), goldenrods (Solidago sp.) and asters (Symphytrichum sp.). 

Large flowered Barbara’s buttons are very rare.  In Kentucky, at the northern edge of its range in the Cumberland Plateau, this plant is extremely endangered and declining.  When we were lucky enough to find a population, only a few single flowers or rosettes had survived.  Many questions remain unanswered about this plants life cycle on the Big South Fork of the Cumberland River. How does this perennial stay rooted in the floods?  How would seed produced ever have the chance to germinate?  I would imagine a deep tap root or an abundance of lateral roots to anchor this plant during the floods, and an ability to live a long life (maybe even thousands of years old), but we just don’t know.  And the mammal or bird dispersed seed taking root in the dry months of the summer, quickly sending its taproot to prevent it from being washed away in the next flood.  Could a plant’s root break off during a flood, travel downstream and re root in suitable habitat, essentially replanting itself through vegetative reproduction? This is strategy is employed by the Cumberland rosemary (Conradina verticillata), but it is unclear weather Marshallia is able to do this. But a shift in flooding patterns, and changing climate, bring uncertainty and could prevent a seedling from taking hold.    There are so many unknowns and confounding factors in the life cycle of this plant.

Life on the river scour can be harsh.  Brutal even. For both its inhabitants as well as surveyors like ourselves.  There are copperheads and rattlesnakes hiding within these prairies, with massive boulders and logjams slowing our travel. Bouldering and rock hopping is necessary to navigate the jumbled debris. With the rains come floods that roar through the gorge, scouring everything in its path.  It’s amazing to me that anything can survive that.  But it is this very disturbance that maintains these “prairies of the river,” for without the flooding and scour, shrubs and trees would take hold and the prairie grasses and forbs would disappear.  Couple this flooding with summer droughts to keep the trees and shrubs at bay, and the river prairies thrive.  Dam these rivers and everything disappears.

Little is known about how long these plants have been hiding out amongst the boulders of the river scour. Likely these disjunct populations from Pennsylvania to Tennessee were connected in the ancient Appalachian landscape. Probably they were more common, and may have evolved within a much more expansive upland ancient prairie habitat that has long ago vanished due to natural large scale climate change, as well as a more connected river scour habitat that is now nearly lost due to damming of rivers and degradation of plant communities from invasive plants, loss and alteration of disturbance regime, and a changing climate. There is even new research into the genetic differences among the extinct North Carolina populations with the rest of the population range, suggesting that there are two different species uniquely evolved in isolation.  So what is our role in conserving this unique species?  One can only speculate that this species is an ancient plant of a lost world, perhaps evolved in in the ancient upland grassland habitat, but now only found in sheltered ravines codependent on the floods of our protected wild rivers to maintain its habitat and ensure its further existence.

Other interesting rare plants that we encountered on the river scour this year include the globally rare Rockcastle aster (Eurybia saxicastellii), Balsam ragwort (Packera paupercula var. paupercula), Turk’s-cap lily (Lilium superbum), golden club (Orontium aquaticum), the federally threatened Cumberland rosemary (Conradina verticillata) and the boulder bar goldenrod (Solidago racemosa).  Included in the mix are intriguing mysteries of possible news species.   But there is one rare plant that we encountered on the river scour that has always intrigued me by its glacial relict past, as it seemed to tell the story of these lost worlds with more clarity, of large scale plant migrations over spatial time that us humans can only begin to comprehend, the sweet fern (Comptonia perergina). 

Sweet Fern-an ancient glacial relict plant lost in the south

The wax myrtle or bayberry family (Myricaceae) is known for its odor.  These plants have resinous dots on their leaves, making them aromatic.  Plants in this family have a wide distribution, including Africa, Asia, Europe, North America and South America, missing only from Australia.   Myricaceae members are mostly shrubs to small trees and often grow in xeric to swampy acidic soils.  Familiar members of the wax myrtle family include many in the Genus Myrica (sweet gale, wax myrtle), some of which are used as ornamentals and are economically important.  In addition, the wax coating on the fruit of several species of Myrica, has been used traditionally to make candles.   

So what place does this interesting family have in Kentucky’s flora?  We are lucky to have one species in the wax myrtle family, sweet fern (Comptonia peregrina).  In addition, it is also a monotypic genus restricted to eastern North America meaning the genus Comptonia has only one species (C. peregrina) worldwide, and we are lucky it is found here in Kentucky! 

The common name sweet fern is misleading.  This woody shrub is certainly not a fern.  However, the leaves have a similar shape to pinnules of a fern frond.  But having sweet in the common name is no mistake.  If you crush the leaves, a lovely smell is emitted as the essential oils volatilize into the air.

Sweet fern is a clonal shrub that grows up to one meter high and spreads through rhizomes. The leaves are alternate and simple, linear and coarsely irregularly toothed, dark green above and a bit paler below.  It is monoecious meaning male and female flowers occur on different plants.  The female flowers are not showy—short rounded catkins that are dense cluster of apetalous flowers, usually associated with oaks, birches and willows with reddish bracts.  The male flowers are elongated yellow-green catkins clustered at the branch tips, the pollen being adapted to wind dispersal.  The fruit is a round, bur-like cluster of ovoid nutlets that turn brown when mature in late summer.  The bark is reddish and highly lenticeled with small corky pores or narrow lines on the bark that allow for gas exchange. 

While common in the northern part of its range (northeastern United States and Canada), sweet fern is state listed endangered in Kentucky, along with being state listed as rare in Ohio, Tennessee, South Carolina, West Virginia, Georgia, and North Carolina.  The populations of sweet fern in the southern part of its range are isolated and disjunct from the common habitats up north.  There seems to be a close association of these remnant populations with the Appalachian Mountains, which suggests that the populations in the southern ranges remained in protected “refugia” during periods of great plant migrations that followed glacial cycles.   

Sweet fern is typically found in openings in coniferous forests with well drained dry, acidic sandy or gravely soils with periodic disturbances.  In the north, it can be found in pine-oak barrens or jack pine and spruce forests that are maintained by fire, creating openings and decreasing competition.  It has also been noted to colonize road banks and even highly disturbed soils such as mined areas.   Contrary to these open coniferous habitats with periodic fire, the remnant populations of sweet fern in Kentucky and Tennessee are found on sandstone cobble bars, which are maintained by annual floods.  Despite being found on habitats that are maintained by different disturbance regimes, these two communities share a few things in common—they are both dry, acidic, sandy and nutrient poor.  Disturbances are a natural occurring impact in these communities that removes shrubs and saplings, thus decreasing competition so that sweet fern can thrive.

But perhaps the most fascinating facts about the rare shrub sweet fern is what it can tell us about the evolution of plants, the history of the earth, and the paleovegetational past of Kentucky.  Geologically speaking, sweet fern is an ancient plant.  In Kentucky, it was likely more common 20,000 years ago during the last glacial period, as Kentucky’s climate was much more like present day Canada.  Analysis of pollen in sediment cores taken from natural ponds in Kentucky confirms that spruce and jack pine was common in the uplands in the bluegrass.  Sometimes it is difficult to imagine plants migrating north and south in order to adapt to a changing climate.  But what is even more mind blowing is that the genus Comptonia is at least 65 million years old.  Numerous fossils of dozens of extinct species of Comptonia have been found all across the Northern hemisphere, and the earliest of the fossils have been dated back to the Cretaceous period during the age of the dinosaurs. The first flowering plants evolved only 135 million years ago, making Comptonia is one of the oldest living plants in the world—a true living fossil!

When April 2020 comes around, and all of the spring wildflowers are emerging, think of sweet fern tucked deep into the gorges of Big South Fork, its catkins releasing pollen in the wind, think of Barbara’s buttons withstanding the massive seasonal floods of one of Kentucky’s last wild rivers.  And if you use your imagination, you may be also be able to see dinosaurs and tree ferns in the distance.   Let us hope sweet fern and Barbara’s buttons can survive for many millions of years to come.

The Lady Slipper, the newsletter of the Kentucky Native Plant Society, has been published since 1986 (see all back issues here). Published three to four times a year, The Lady Slipper contains a mix of news, upcoming events, and articles about the native plants of Kentucky.

The very first issue, Vol. 1, No. 1, February, 1986, was typewritten. In 1995, a contest was held to name the Society’s newsletter. The winning name, The Lady Slipper, was introduced in Vol. 11, No. 1, February, 1996, the start of the 10th year of publication. With Vol. 23, No. 3, Fall, 2008, we began publishing our newsletter in color.

With this issue (Vol. 34, No. 2, Summer/Fall 2019) we are changing the format of The Lady Slipper, to a blog format on our website

We are in need of someone willing to take on the job of Editor. The editor solicits and collects articles for each issue. The articles are put into the WordPress blogging platform and then formatted and edited. Experience with WordPress would be great, but even if you are not familiar with WordPress, the Society’s webmaster can help you quickly come up to speed.

If you love native plants and like to edit and organize articles, we would love to have you on the team. If you have any questions or have an interest in helping out, just email KYPlants@knps.org

Kentucky Native Plant Society is looking for your help to assist with monitoring Cumberland Plateau pine barrens remnants along roadsides and powerlines in the Daniel Boone National Forests (DBNF). This is a rare plant community in eastern Kentucky. Pine Barrens are open woodlands made up of a mix of sandstone outcrops, grasslands, and open pine-oak woodlands with an open understory. Historically, pine barrens were maintained by periodic fire keeping the understory and canopy open. Due to logging and fire suppression, this community is greatly reduced and altered in Kentucky. The majority of the remnant pine barrens in Kentucky are restricted to powerline corridors and roadsides in the DBNF. Consequently, many of the plants once associated with this plant community are also rare. Wood lily (Lilium philadelphicum) for example, is restricted to this habitat in Kentucky and can be found primarily on roadsides of the DBNF. Population numbers of wood lily have plummeted in recent decades. Numerous other plants of concern also depend on this habitat including Ten-lobed False Foxglove (Agalinis decemloba), Yellow Wild Indigo (Baptisia tinctoria), Bearded Skeleton-grass (Gymnopogon ambiguous), Southern Crabapple (Malus angustifolia), Appalachian sandwort (Minuartia glabra), Racemed Milkwort (Polygala polygama), Hairy Snoutbean (Rhynchosia tomentosa), Chaffseed (Schwalbea americana), Eastern Silvery Aster (Symphyotrichum concolor), and Roundleaf Flameflower (Talinum teretifolium).

Knowing where plants occur is the first step towards protecting them. If you wish to help, please fill out this Signup Form and we will give you a section of DBNF roadside/powerlines to monitor over the coming growing season. We will utilize the smartphone app iNaturalist as a means of documenting the rare plants you find.

The app iNaturalist has grown from a graduate project at U.C. Berkeley to a global community of naturalists looking to connect people and nature through technology. The goal of the app is to allow citizens scientists, like yourself, to record biodiversity. Photographs taken with your smartphone are uploaded to the app, along with location data, where naturalists from across the world help identify the organism. By posting your photographs, you can contribute to a better understanding of the range and abundance of plants and animals. Kentucky Native Plant Society will track your photographs of plants along DBNF roadsides in an effort to protect these rare plants and remnant ecosystems. Hopefully, these efforts will go a long way towards protecting the Cumberland Plateau pine barrens remnants and the rare plants associated with them.

Citizen Scientists contribute to continental scale study to assess variation in nitrogen use of red maple (Acer rubrum)

By: Steve Gougherty*
* PhD Student, Finzi Lab, Department of Biology, Boston University

Nitrogen dynamics in plants

In terrestrial ecosystems, plant growth is commonly limited by the availability of nitrogen. Nitrogen is a critical element for plant health as it is incorporated into key molecular structures such as chlorophyll, which absorbs light energy during photosynthesis, and enzymes (e.g., RuBisCo, which is responsible for fixing carbon dioxide from the atmosphere as part of photosynthesis). Many plants start life with a nitrogen reserve in their seeds, but eventually come to rely on their root system to absorb nitrogen from the soil to satisfy their demand.

Acquiring nitrogen from soil can be a costly endeavor for plants, and perennial plants have developed strategies to more efficiently use the nitrogen they have already acquired. For example, deciduous trees effectively recycle nitrogen at the end of each growing season through a process known as foliar nitrogen resorption. Foliar nitrogen resorption involves the breakdown of nitrogen containing compounds (like chlorophyll and enzymes) in the leaf and the transfer to other tissues in the plant, such as developing buds. In fact, the breakdown of chlorophyll in leaves and transfer to other plant tissues is partially responsible for the ‘fall colors’ in eastern temperate forests. Even though researchers know that foliar nutrient resorption is an important component of tree’s annual nitrogen budget, extremely little is known about how variable this process is throughout geographic ranges of plants. This is an important question because understanding the nature of nitrogen limitation on plant productivity is an active area for ecologists studying energy and carbon balances of ecosystems.

Citizen Scientist role in addressing questions about red maple nitrogen use

Red maple (Acer rubrum) is one of the most abundant and broadly distributed tree species in North America (Figure 1; green shading shows approximate distribution). Its abundance and broad distribution makes it an excellent candidate to assess the potential for variation in key nutrient retention strategies, such as foliar nitrogen resorption. However, sampling red maple throughout its geographic range is a major logistical challenge for an individual researcher. As a result, I started a Citizen Science project that invites participants to sample red maple leaves in their local areas and send them to a research laboratory for processing and analysis. A broad network of Citizen Scientists is ideal for this project for several reasons: 1. Citizen Scientists know where to find red maple trees in their local areas. 2. The network allows for the potential to obtain samples from nearly the entire geographic distribution of red maple in the United States. 3. Since Citizen Scientists sample locally, it makes the two sampling time points (once when leaves are green, and once at leaf fall) feasible.

2019 was the initial year of the project and over 120 Citizen Scientists signed up to participate in the project (Figure 1; magenta dots). As leader of this project I am extremely grateful for the response we have received and look forward to disseminating our results to our Citizen Scientists and the scientific community over the course of the project. Participants interested in collecting in 2020 are welcome to sign up on our website at any time.

Getting involved in the project

Interested members of the Kentucky Native Plant Society and readers of The Lady Slipper are invited to learn more about the project at our website: sites.bu.edu/tasper . On our website we have more information about our research questions along with a signup form for participants, and sampling protocols.