Get ready and be observant on these cold mornings. We are now entering the time of year when we will begin seeing one of Nature’s loveliest and most evanescent phenomenons in our region; Frost Flowers.
What are Frost Flowers?
Frost flowers are thin ribbons of ice that form on the stems of a few species of native plants. Water from the roots is drawn up the stems (either as part of the plant’s natural transportation system or through capillary action) and expands as it freezes, breaking the stem walls and creating a flow of ice. As the ice forms, more water freezes, forcing out ribbons of thin ice . Other names for these structures are “ice flowers”, “ice ribbons”, “ice fringes”, “ice filaments”, and “rabbit ice”.
Conditions Needed for Frost Flowers to Form
Frost flowers form only when certain very specific conditions all come together:
Air temperatures must be below freezing (usually below 30°).
There should be little to no wind.
Ground temperatures must still be above freezing.
There must be some degree of soil moisture.
They only form on particular species of plants.
If conditions are right, the same plants can produce multiple frost flowers in a season, starting as early as November and producing frost flowers as late as early February. Usually the first frost flowers of the year will extend quite a ways up the stem, without extending out very far, as the entire stem splits. By the end of the season, when the stems are completely shredded, the frost flowers come out from the very base of the plant.
What Plants Produce Frost Flowers?
Worldwide, there are roughly 30 species of plants that produce frost flowers. In our region there are three native species that typically produce frost flowers. The two most common are white crownbeard, a.k.a. frostweed (Verbesina virginica) and common dittany (Cunila origanoides). A third species, that is mainly in wet areas, is marsh fleabane (Pluchea camphorata). I have heard that frost flowers sometimes appear on species of sage (Salvia) but I have never seen that and don’t know for sure what species of sage may produce frost flowers.
Frostweed (Verbesina virginica) Perennial herb, 3-7 ft. tall with winged stems. Leaves are alternate, broadly lanceolate, 4-8 in. long, with winged petioles. Flowers August – October
Dittany (Cunila origanoides) Semi-woody perennial, 12-18 in. tall with a strong odor. Leaves are opposite, oval, 1-1 1/2 in. long. Flowers August – October
Marsh Fleabane (Pluchea camphorata) Short lived perennial, 2-5 ft. tall with a camphor like odor. Leaves are alternate, broadly lanceolate, 3-10 in. long. Flowers August – September
Grow Your Own Frost Flowers
Although it is always exciting to find frost flowers in the “wild” another option for folks is to plant one of the natives that produce this phenomena in the yard. My frostweed patch came from a single plant that volunteered in the front yard about 6 years ago. It has reseeded itself and now many others have sprouted from the seeds of the original. On cold mornings I can now just look out the front window and see the frost flowers.
On Saturday, Oct. 23, KNPS held a virtual Fall Member meeting. The meeting was a review of what the Society has done in the past year and we discussed upcoming activities for the rest of 2021 and for 2022. View the full meeting here.
By Tony Romano, OKNP botanist/Conservation Coordinator
Figure 1: A remnant grassland with eastern whiteflower beardtongue (Penstemon tenuiflorus) in Logan County
Grasslands are an increasingly rare plant community type in Kentucky and the southeastern United States. Kentucky has often been depicted as a continuous forest, but we now understand that grasslands (defined broadly here to include prairie, savanna, barrens, and woodland communities) were once much more widespread throughout the state. Estimates of pre-settlement grassland communities in Kentucky range from 2.5 to 3 million acres. These grasslands are now nearly gone, with less than 1 percent of natural prairie and barrens remaining today in Kentucky (Abernathy et al. 2010). Much of this loss can be attributed to direct conversion of habitat through agricultural and urban development. The cessation of historical disturbances such as fire and grazing by large herds of animals has allowed the remaining grasslands to be degraded and slowly converted into forests by woody succession.
Figure 2: Purple milkweed (Asclepias purpurascens), state watch list species, with great spangled fritillary (Speyeria cybele).
Figure 3: A rare limestone glade remnant in Breckenridge County.
Figure 4: Roadside wet meadow with swamp milkweed (Asclepias incarnata) and eastern carpenter bee (Xylocopa virginica) and Sachem (Atalopedes campestris) butterfly.
Figure 5: Ecologist and writer Aldo Leopold. Courtesy of the Aldo Leopold Foundation and University of Wisconsin-Madison Archives
Aldo Leopold, a name that looms large in ecology, recognized over 70 years ago that roadsides were some of the last bastions of the mid-west tallgrass prairie in Wisconsin and Illinois. Even in Leopold’s time, most of the tallgrass prairie in the mid-west was already lost to the same processes that have diminished Kentucky’s grasslands. A Sand County Almanac, a collection of Leopold’s essays published posthumously in 1949, is a seminal work of ecological and philosophical writing that continues to influence the thinking of ecologists and conservationists to this day. While re-reading Almanac this past winter, I was struck by two essays that had direct bearing on the topic of this article. In Prairie Birthday, Leopold describes a remnant prairie tucked in the corner of a cemetery which borders a highway. He describes a stand of compass plant (Silphium laciniatum), perhaps the last population in that county, that blooms each July in that cemetery. Sadly, the fence separating the prairie from the road is eventually removed and the Silphium is mowed. Leopold laments that “this is one little episode in the funeral of the native flora, which in turn is one episode in the funeral of the floras of the world.”
Recognizing that things don’t need to be this way, Leopold continues “…every highway is bordered by an idle strip as long as it is; keep cow, plow, and mower out of these idle spots, and the full native flora … could be part of the normal environment of every citizen.”
In a later essay, Illinois Bus Ride, Leopold describes the vestiges of native plants and animals that he observes out the window of a bus traveling through Illinois. He notes that “In the narrow thread of sod between the shaved banks and toppling fences grow the relics of what once was Illinois: the prairie.” The foresight of these essays, that roadside remnants would become vital for grassland conservation, is truly astounding.
Figure 6: Newly discovered roadside population of barrens silky aster (Symphyotrichum pratense)(G4/S3).
Figure 7: Prairie dock (Silphium terebinthinaceum) along a roadside in Meade County.
In recent years, roadsides and utility right-of-ways have been increasingly recognized by ecologists and land managers for their potential conservation value. Research has shown that roadsides can provide important habitat for many pollinating insects, including at-risk species like the monarch butterfly (Hopwood 2008). Because they are maintained in an open, grass dominated state, roadsides can also contain remnants of native grassland communities that support diverse and sometimes rare plant species. Importantly, research shows that intact, high-quality, grasslands provide some of the best habitat for pollinators due to the abundance and diversity of plant species that occur in these communities (Ries et al. 2001). In other words, if we can protect high-quality roadside grasslands, we will also be providing vital habitat to insect populations. Nationwide, approximately 10 million acres of roadside right-of-ways are managed by state transportation departments (Forman et al. 2003). If successfully managed for native plant species, ten million acres is a tremendous amount of potential pollinator and grassland habitat.
Fortunately, Leopold’s old idea has gained traction. At the federal level, an important 2014 Presidential Memorandum addressed concerns over the monarch butterfly and declining populations of important pollinating insects. The memo directed federal agencies to increase or improve pollinator habitat nationwide (White House 2014). The memo additionally directed the Federal Department of Transportation to work with state departments of transportation to promote pollinator friendly practices. In accordance with this memo, the Federal Highway Administration researched and published several documents outlining best management practices (BMPs) and restoration techniques for managing roadside right-of-ways for native plants and pollinating insects (U.S. Department of Transportation, 2016).
Figure 8: OKNP’s progress so far on roadside pollinator habitat and grassland surveys
Figure 9: Appalachian rosinweed (Silphium wasiotense) a globally rare plant (G3/S that thrives on roadsides.
In the Commonwealth, the Office of Kentucky Nature Preserves (OKNP) and the Kentucky Transportation Cabinet (KYTC) have partnered on a 5-year project to survey all of the state maintained roads for high-quality pollinator and grassland habitat. KYTC maintains approximately 31,000 miles of roadside right-of-way which includes the interstates, US highways, and all state highways. Surveys began in 2020, and so far our botanists have surveyed over 13,000 miles of road in over 40 counties. We have evaluated over 200 sites for pollinator habitat and have identified over 30 high-quality grasslands. We also identified over 20 additional sites that do not necessarily meet high-quality grassland criteria, but still provide important habitat for certain rare plant species like the Appalachian Rosinweed (Silphium wasiotense). This Silphium is a globally rare species (G3/S3), endemic to Kentucky and Tennessee, that thrives on forest edges along roads in eastern Kentucky. In line with the goals of the Kentucky Pollinator Protection Plan (Kentucky Department of Agriculture 2019), once important sites are identified, we are working with KYTC to modify existing management to support and benefit these grassland communities and rare plant habitats. We believe this work will help preserve the full native flora of Kentucky.
Now, there is a second old idea in Leopold’s essays that I would like to briefly touch on if the reader will permit it. In addition to his concern over the retreating prairie, Leopold was once again ahead of his time when he observed what we would now call “plant blindness” in his contemporaries. In Illinois Bus Ride he comments that “No one in the bus sees these relics. A worried farmer … looks blankly at the lupines, lespedezas, or Baptisias … He does not distinguish them from the parvenu [exotic] quackgrass in which they grow.” Leopold continues “Were I to ask him the name of that white spike of pea-like flowers hugging the fence, he would shake his head. A weed, likely.” In Prairie Birthday he states the issue directly “We grieve only for what we know. The erasure of Silphium from western Dane County is no cause for grief if one knows it only as a name in a botany book.”
Figure 10: “…that white spike of pea-like flowers” isn’t a weed, its white wild indigo (Baptisia leucantha)!
Figure 11: Newly discovered roadside population of round-head bush clover (Lespedeza capitata) (G5/S3).
Figure 12: Tony Romano, OKNP botanist, at a newly found and highly diverse roadside prairie.
Coined in 1998 by botanists Elisabeth Schussler and James Wandersee the term “plant blindness” refers to “the inability to see or notice the plants in one’s own environment” (Allen 2003). Plant blindness among the general public diminishes peoples understanding, interest, and connection to nature. Left untreated, plant blindness can result in declines in funding for plant biology education, research, and conservation initiatives. One of the primary missions of KNPS is to educate the public about plants and alleviate plant blindness. It is my hope that OKNP’s roadside habitat project will contribute to the visibility of native plants and spark interest in learning about and conserving our native flora.
One way that readers could help our efforts is to take a look at your local backroads. OKNP’s roadside survey project is limited to state maintained roads and generally excludes county and local roads. Please join our inaturalist project and help us document important habitat by adding your observations of roadside native plants to the project at https://www.inaturalist.org/projects/kentucky-roadside-native-plants.
References:
Abernathy, G., D. White, E. L. Laudermilk, and M. Evans, editors. 2010. Kentucky’s Natural Heritage: An Illustrated Guide to Biodiversity. University Press of Kentucky, Lexington, KY., USA.
Allen, W. 2003. Plant Blindness. BioScience. 53(10).
Forman, R. T. T., D. Sperling, J.A. Bissonette, A. P. Clevenger, C.D. Cutshall, V.H. Dale, L. Fahrig, R. France, C. R. Goldman, K. Heanue, J.A. Jones, F.J. Swanson, T. Turrentine, and T.C. Winter. 2003. Road Ecology: Science and Solutions. Washington, D.C.: Island Press.
Hopwood, J. 2008. The contribution of roadside grassland restorations to native bee conservation. Biological Conservation. 141.
Kentucky Department of Agriculture. 2019. Kentucky Pollinator Protection Plan. Available at: https://www.kyagr.com/statevet/documents/OSV_Bee_KY-Pollinator-Pro-Plan.pdf. Accessed: October 2021.
Ries, L., Debinski, D.M., and M.L. Wieland. 2001. Conservation value of roadside prairie restoration to butterfly communities. Conservation Biology. 15(2).
U.S. Department of Transportation, Federal Highway Administration. 2016. Pollinators and Roadsides: Best Management Practices for Managers and Decision Makers. Available: https://www.environment.fhwa.dot.gov/env_topics/ecosystems/Pollinators_Roadsides/BMPs_pollinators_roadsides.pdf. Accessed: October 2021.
White House Office of Press Secretary. 2014. “2014 Pollinator Presidential Memo.” Available: https://www.nps.gov/subjects/pollinators/presidential-memo.htm. Accessed: October 2021.
You worked hard turning some of your property into wildlife habitat. You planted nectar and host plants for butterflies and pollinators. Trees and bushes offer shelter and habitat for birds, squirrels, and other small creatures. Perhaps this summer, a box turtle took up residence in your back yard or you heard tree frogs singing in your own trees! Now, after all your hard work, why would you destroy that wonderful ecosystem by cleaning it up for winter?
This time of year, experts encourage us to clean up and cut down. That is the right way to manage a manicured golf-course landscape; but it’s the wrong way to treat the property you’ve cultivated as wildlife habitat. Think about it; does Mother Nature rake leaves and cut down dried seed heads? No. Dying plant matter provides food and shelter for insects and animals throughout the winter, and to complete the lifecycle, decaying matter amends the soil—free fertilizer!
First, let’s talk about not raking leaves. Leaf litter is a microecosystem all its own. It’s full of eggs, larvae, pupae, and thriving insects. Bag up the leaves and they’re gone—an entire little ecosystem is gone. You invited all those beneficial insects into your yard. If you want to keep them there, don’t destroy their home and kill their offspring! Instead, allow leaves to lay where they fall. Only remove leaves from areas you must. A foot of leaves can be as detrimental to that thriving community as no leaves at all. In addition, wet slippery leaves are hazardous. Find balance between being a responsible homeowner and supporting the living community underneath those leaves.
Next up is your wildflowers. They’re looking shabby this time of year, but fight the urge to cut them back. Birds and other creatures depend on seeds and dried leaves for food. Many insects overwinter in dried stems. And honestly, what looks a tad shabby right now will look spectacular surrounded by a blanket of snow. I plant river oats because those glistening seeds bowing over a blanket of bright snow are beautiful. If you want to clean up your front yard a bit, that’s understandable, but don’t throw out the debris. Pile it up in an out-of-the way corner and let nature take care of it while it provides shelter throughout the winter.
Experts tell us that a messy winter garden encourages disease, and they’re right. Please don’t apply this messy strategy to your vegetable garden plots or your precious cultivars, such as roses. Some of your landscape will always require special care. However, in those areas that you purposely turned over to nature, continue to let nature take the lead.
Butterflies, native bees and pollinators, and other beneficial insects need a safe place to hibernate over winter. Birds and other small creatures need shelter and food. Truly wild places are in decline, so your yard matters. Every yard matters. Leave your wildlife habitat messy, and let nature do what it does best in a healthy balanced system.
This article was originally published in the Franklin County Horticulture newsletter.
Please join us for the 2021 KNPS Fall Meeting on October 23, from 4PM to 5:30PM EDT. We will be meeting virtually again this year on Zoom (hopefully our last virtual Fall Meeting). Our fall meetings are open to members and non-members alike. The meeting will review what the Society has done in the past year and discuss activities for the rest of 2021 and for 2022. As the meeting is on Zoom, please register by following the link at the bottom of this article. If you want to learn more about your Society the KNPS Fall Meeting is for you. If you have any questions, email us at KYPlants@knps.org.
Meeting Agenda
4:00PM to 4:25PM – Welcome and Review of 2021
Welcome – Tara Littlefield
Wildflower Week 2021 – Heidi Braunreiter
2021 Field Trips – Tara Littlefield
The Lady Slipper – Susan Harkins
Student Grants – David Taylor
Financial Report – Steele McFadden
Membership Report – Jeff Nelson
KNPS Board Secretary – Tara Littlefield
4:25PM to 4:40PM – Botanical Symposia – Tara Littlefield
5:00PM to 5:30PM – Standing Committees & Member Engagement – Jeff Nelson
Registration
As the meeting will be virtual, registration is required. Complete the registration form at this link and you will receive a link to the virtual meeting.
KNPS is hosting a virtual botanical symposium on Wednesday, December 8th from 9AM-12PM EST. For several years, KNPS has organized a botanical symposium in the fall/winter with a goal of bringing together professionals, citizen scientists, academics, gardeners and students in order to learn about what’s going on in the world of Kentucky Botany. Please join us to learn about all things botanical in Kentucky and the surrounding region.
Topics that will be covered will include, but will not be limited to, KNPS updates, plant conservation alliance updates, conservation horticulture and native plant propagation; monitoring and managing native and rare plants and natural communities,; native plant research; plant biodiversity in Kentucky and the surrounding regions and exciting new botanical discoveries.
Mountain lover (Paxistima canbyi) in Carter County, Kentucky (Photo by T. Littlefield)
Limestone outcrops/Mountain Lover habitat overlooking the Cumberland River in Pulaski County, Kentucky (Photo by T. Littlefield)
Mountain Lover (Paxistima canbyi) is a globally rare (G2), small evergreen shrub in the bittersweet family (Celastraceae). This shrub is occurs in Kentucky (S2), Maryland (S1), Ohio (S1), Pennsylvania (S2), Tennessee (S1), Virginia (S2), and West Virginia (S2), and is listed as state threatened or endangered throughout its range. This interesting shrub grows clonally and can form dense patches with stems reaching 6-12 inches. Fruit development and seed production are reportedly quite rare in the wild and there may be fewer than sixty genetically distinct plants throughout its entire range due to its clonal nature, further compounding its rarity.
One interesting note about the mountain lover is that it is thought to be an ancient glacial relict species, a remnant from a long lost ecosystem that occurred in this region prior to the last glaciation some 20,000 years ago. The late Dr. E. Lucy Braun, the esteemed plant ecologist from Cincinnati, had an interest in this plant and speculated that the mountain lover was an ancient glacial relict species that occurred along a pre glacial river system called the Teays River. I wonder how long these remnant populations have been clinging to the limestone cliffs and how old the root systems are of these clonal shrubs, perhaps thousands, even tens of thousands of years old?
Mountain lover has very small green/marron flowers with four sepals and four petals arising from upper leaf axils. While I occasionally see it flower, i have never found any fruits (photo by: T. Littlefield)
Global Range of Mountain Lover. http://bonap.net/MapGallery/County/Paxistima%20canbyi.png
Natural regions where mountain lover is found in Kentucky
I have long been fascinated by this plant and the limestone cliff and outcrop habitats where it grows. In Kentucky, It occurs in several sub regions of the interior low and Appalachian plateaus, including the inner bluegrass, the knobs, and the cliff section/intersection of the eastern highland rim and Cumberland Plateau. It is associated with limestone rocky ledges and cliffs, with an overstory/midstory of Chinkapin oak (Quercus muehlenbergia), Blue Ash (Fraxinus quadrandulata), Eastern Red cedar (Juniperus virginiana), and eastern hophornbeam (Ostrya virginiana). The herbaceous/shrub layer includes shrubby st. johns wort (Hypericum prolificum), fragrant sumac (Rhus aromatica), smooth rockcress (Boechera laevigata), limestone cliff sedge (Carex eburnia), purple cliff break fern (Pellaea atropurpurea), and wild columbine (Aquilegia canadensis). The limestone cliffs and outcrops typically occur in deep ravine gorges that form unique microclimates that also provide habitat for other glacial relict disjunct rare species such as Canada yew (Taxus canadensis), walter’s violet (Viola walteri), northern white cedar (Thuja occidentalis), glade phlox (Phlox bifida var. stellaria), purple oat grass (Schizachne purpurscens) and snow trillium (Trillium nivale). The overall community assemblages of the mountain lover sites are unique between the various regions, and we are currently working with NatureServe to classify these plant communities to determine global rarity and classifications.
Walters violet (Viola walteri, S1) grows with mountain lover in Carter county, KY, Photo: T. Littlefield
Canada yew (Taxus canadensis, S1), glacial relict disjunct rare plant grows with mountain lover in Carter county, KY, Photo: T. Littlefield
Gnarly Eastern red cedars (Juniperus virginiana) grow on the limestone cliffs/mountain lover habitat in Estill county, KY, Photo: T. Littlefield
Overlook at a mountain lover site in Estill county, KY, Photo: T. Littlefield
Northern White Cedar (Thuja occidentalis, S1), a glacial relict disjunct rare tree, grows with mountain lover in Wayne county, KY, Photo: T. Littlefield
View from below the limestone cliffs at a mountain lover site in Madison county, KY, Photo: T. Littlefield
Another common name of this plant is the “rat stripper” due to its relationship with eastern wood rats (Neotoma magister) that co-occur in the limestone outcrop habitats. These animals have been known to sever the woody stems to utilize in nests building along the cliffs. I have personally observed this phenomena at one of our Kentucky sites in Estill County, where I came upon a population with hundreds of freshly severed stems, wood rat tracks and nesting signs. I collected a few of the fresh cut stems and rooted them in potting mix after that trip. Could wood rats also play a role in expanding mountain lover populations along the cliff lines by inadvertently planting some as they drop stems along the cliff lines?
Major threats to the mountain lover include invasive plants such as bush honeysuckle (Lonicera maackii), Euonymus scale (Unaspis euonymi, a small non-native aphid-like bug), timber removal, deer browsing and climate change. The majority of populations occur on private lands so development of the cliff tops has impacted a few populations and could be a threat to several more. Perhaps the greatest threat in Kentucky appears to be from the Euonymus scale, with over 50% of our populations experiencing declines due to this nonnative bug. Euonymus scale not only effects populations of mountain lover, but most species in the bittersweet family are affected as well, such as the eastern wahoo (Euonymus americana) and American bittersweet (Celastris americana). Due to the steep, cliff habitat where mountain lover occurs, there could be undiscovered populations that are inaccessible to humans. Additional surveys for new populations could further our understanding of the species and help evaluate its conservation status.
Euonymus scale infestation on Mountain Lover population in Madison County, Kentucky. Photo by T. Littlefield. For more info on Euonymus scale visit https://entomology.ca.uky.edu/ef428
Medium infestation of Euonymous scale in a mountain lover population in Powell county, note yellowing of leaves, several dead patches were nearby, Photo by T. Littlefield
We know that mountain lover is globally rare, has numerous threats, and occurs primarily on private land. So how can we work together to preserve this unique species? Conservation measures include networking with landowners that harbor mountain lover populations, targeting land acquisition projects to include these priority private sites, manage populations for the euonymus scale, and increase ex situ conservation efforts with horticulturalists. In June of 2021, recent efforts by the Office of Kentucky Nature Preserves, Kentucky Plant Conservation Alliance, and the Atlanta Botanical Garden along with partners at the Daniel Boone National Forest, Berea College forest and several private landowners focused on visiting populations in all of the sub regions in Kentucky and collecting living samples to propagate for ex situ conservation and future introductions. Site evaluations, natural community assessments and rare plant updates were also conducted as a part of this collection trip. Having additional sites on public lands would allow researchers and biologists more opportunities for monitoring and managing these populations into the future. Conservation horticulturalist John Evans at the Atlanta Botanical Garden is now currently growing plants from 5 populations in Kentucky for future introductions within OKNP natural areas in the inner Bluegrass, Daniel Boone national Forest lands in the Cumberland Plateau, and Berea college forest sites in the knobs region.
Calab Evans, Atlanta Botanical Garden Horticultural technician, roots cuttings of Mountain lover from recent collection trips
John Evans, conservation horticulturalist at Atlanta Botanical Garden, and Tara Littlefield, OKNP/KPCA botanist hanging out on limestone cliffs on a recent collection trip
If you would like to know more about these efforts or other Kentucky Plant Conservation Alliance efforts to conserve the rare plants and communities in Kentucky, please contact tara.littlefield@ky.gov.
