By Jeff Nelson, KNPS President
The purple fringeless orchid (Platanthera peramoena A. Gray) is one of Kentucky’s 40+ native, terrestrial orchids. It is widespread in Kentucky, though uncommon. The species is found in moist forests, woodlands, meadows, and thickets, as well as in marshes and swamps. It grows from 1’-4’ tall, producing 2-5 spreading leaves along its stem. In early to mid-July the plant bears an inflorescence of multiple, showy, pink or purple flowers.
In 2016, I came across a single volunteer specimen of P. peramoena growing in moist woods on our 10 acres in SW McCracken county, Kentucky. At the time I am writing this, in early July of 2024, there are fifteen plants, twelve of which are flowering. In this post I am going to go through the processes that led to the (so far) successful expansion of this population of orchids.
Background
In 1987, my wife Liz, our son Aaron, and I moved onto 10 acres of farmland located in rural, southwest McCracken Co., Kentucky. Our long term goal was to restore this farmland to native woodland with as much native ecosystem diversity as possible. Our approach to this restoration followed a simple rule:
“Let every seed sprout. When it can be identified, if it is non-native, kill it. If it is native, let it grow and fight it out with other natives.”
Although most of our property was agricultural, there were two narrow strips of large native trees along the wet-weather creeks on the north and east side of the property. These strips provided a seed bank for native tree and forb species to colonize the open space. We also collected wild seed from our region and spread that on the place. In the early years much of what came up was non-native, and some of those were seriously invasive species, most notably Japanese honeysuckle (Lonicera japonica) and Oriental bittersweet (Celastrus orbiculatus). Most of our efforts were concentrated on removal of the invasive species but we were pleasantly surprised at how quickly native trees and forbs began growing. At the present time, we have a young, native woodland with at least 35 species of native trees and over 200 species of native forbs, graminoids, shrubs, and ferns.
Discovery
In June of 2016, as I was walking around our woods, I noticed a plant that I had never seen before. It was a single stalk, about 2′ tall. There were a few, alternate, lanceolate leaves ascending the stem. At the top of the stem was a budding inflorescence. Although I did not know what it was, I suspected it might be a native orchid. Doing research and posting images of the plant online in the Kentucky Native Plant Society Facebook Group, to get input from other botanists, I was fairly confident that it was a species of Platanthera, and because of the location in our acidic, moist woods, in McCracken county, I was leaning towards purple fringeless orchid (Platanthera peramoena).
I flagged the plant so I could locate it again and put a wire cage around it to discourage any potential herbivory. Since it was in bud I visited the plant almost every day planning to see it in flower and confirm its identity. As the days passed, the pedicels elongated and the buds swelled and I was looking forward to seeing the flowers for the first time to confirm my ID. Then one day, I noticed that all of the buds were turning brown and they never opened. Still not sure what caused this to happen to all of the buds, but experts at the North American Native (and Naturalized) Orchids Facebook group have suggested thrips as a possibility.
In 2017, the orchid came back and grew well. By June there were many buds on the inflorescence and by July the orchid was in full bloom. With flowers visible, I was able to easily confirm that it was indeed a volunteer purple fringeless orchid (Platanthera peramoena).
Pollination
With this one healthy orchid growing well in our woods I began thinking about how I might be able to help develop a self sustaining population. Researching the species online, I found that, like many native orchids, purple fringeless orchid is self infertile and must be cross pollinated from another individual. In the wild, this orchid is known to be pollinated by monarchs (Danaus plexippus), snowberry clearwing moths (Hemaris diffinis), hummingbird clearwing moths (Hemaris thysbe), eastern tiger swallowtails (Papilio glaucus) and spicebush swallowtail (Papilio troilus.) I was not aware of any other orchid populations nearby so I concluded that even though we have all of those species of Lepidoptera in our woods, the solitary purple fringeless orchid was unlikely to reproduce in our woods.
In 2018, my friend Pat Ranval introduced me to Alexander Walker. Alexander was a long time orchid enthusiast, serving as president of the Paducah Orchid Society for a time. He was also a skilled orchid propagator. Most of Alexander’s orchid growing experience was with tropical, epiphytic species. He was interested in learning more about our native, terrestrial orchids. I invited Pat and Alexander to come out to our place to check out the purple fringeless orchid just as they were beginning to blossom at the end of June, 2018. As we were discussing the fact that the purple fringeless orchid was self infertile, Alexander told me that if I could find another source of orchid blossoms, he would be willing to attempt to hand pollinate my specimen.
I reached out to social media and connected with Mike Chervinko in Carbondale, Illinois. He knew of a site with multiple populations. I drove up to Carbondale and met Mike at the site. We saw multiple separate groups of purple fringeless orchid in bloom. I was able to get six flowers, taking one flower from one inflorescence in each group. The six flowers went into a small plastic container in an ice chest for the 60 mile drive home. Once home I put the flowers in the fridge and messaged Alexander.
Before we get into the hand pollination process a little bit about orchid flowers and the natural pollination process might be helpful. Orchids have a unique flower structure which consists of four main parts. The orchid flower is typically has an outer whorl of three sepals, an inner loop of three petals, a single large column in the center, and an enlarged bottom petal called a lip or labellum. At the top of the column is the anther, which contains packets of pollen, called pollinia, and below the anther is the stigma, a shallow, sticky cavity in which the pollen is placed for fertilization. Pollinia are covered with a sticky substance and are positioned so that as a pollinator feeds at the flower, the pollinia are attached to the pollinator, which in turn carries the pollinia to another flower. When a pollinator arrives at a flower, if it has pollinia from another flower already attached, the stigma can receive the pollen contained in the pollinia. This is a much simplified explanation of a fascinating and complex process. For a more in depth look at the process I refer to this PDF from the University of Florida, Orchid Pollination Biology, Haleigh Ray and Wagner Vendrame.
The next day, July 8, 2018, Alexander came over to our place. First, he closely examined each of the orchids I had brought down from Carbondale. He determined that three of the flowers had pollinia ready to pollinate. We walked down to the orchid in our woods and he meticulously transferred the pollinia to flowers on the plant that had receptive stigma. The slideshow below shows Alexander hand pollinating the orchid.
So began the waiting game. Most days I would walk down to the orchid and look to see if I could tell if the pollination was successful. I thought that the senescence of the flowers that were pollinated looked different from other blossoms at the same stage that had not been pollinated, but was not sure. Then, nine days after the hand pollination, on July 17, I took a picture of what I believed to be developing fruit. I messaged the image to Alexander and he confirmed, we had pollination.
The seed pods on the orchid continued to develop and enlarge into the fall. We wanted to let the bulk of the seeds distribute on their own through normal processes. In addition, Alexander wanted to experiment with propagating Platanthera peramoena from seed. I collected the seed pods and the remaining seed in mid-November and gave them to Alexander. Unfortunately, he was unable to get the seeds to germinate in the lab.
Restoration Success
In early April, 2022, four years after our hand pollination experiment, I was walking around our property, making observations for the KNPS Wildflower Week 2022 Botany Blitz. Wanting to get an observation of the purple fringeless orchid as it was first sprouting I headed towards the location of the orchid. Approximately 10′ from the original plant I happened to notice an orchid-like sprout. Looking more closely I saw that it looked identical to the original. Needless to say I was very excited. The hand pollination of the original individual had successfully resulted in a second plant.
Over the next few weeks, I continued to observe the area and found several more orchid sprouts. In all I found a total of ten orchids, nine of them were new plants. By July, there were six orchids in full flower, so I was hopeful that natural pollination would occur. Unfortunately I hadn’t done my research on what insects pollinated the species. I had protected each flowering plant from potential herbivory with chicken wire cages. It wasn’t until the flowers were done blooming and none of them were pollinated that I actually looked up the pollinators (monarchs, clearwing moths,eastern tiger swallowtails, and spicebush swallowtails) and realized that there was no way that the large butterfly pollinators of purple fringeless orchid could access the flowers through the cages. I removed all of the wire cages and built a shade cloth fence around the patch.
In the spring of 2023, I began regular observations of the orchid patch. All but one of the orchids that had grown in 2022 returned in 2023. And there were two new orchid sprouts in the patch. The plants did great during the growing season with six plants in full flower. I never saw butterflies around the plants, but in the middle of July, I did not go down every day nor did I stay long there, but was hopeful that pollination would occur.
As the summer progressed it soon became obvious that many of the flowers had gotten pollinated. There were ripening fruits on three plants and one had a very large number of fruits. I was incredibly excited and overjoyed. There was now a potentially self-sustaining population of these uncommon and beautiful native orchids.
Current Status, July 2024
In the spring of 2024, I started making regular walks down to the orchid patch. All of the plants in the patch from 2023 were coming back. One plant that had flowered in 2022, and then had died back in 2023, was sending up a new leaf. With plenty of rain this spring, I pretty much left the orchids to do their thing. Then in June I went down to do a survey of how many plants were budding out. At least six plants were preparing to flower again. As I left the fenced patch and headed towards the creek something light colored caught my eye. Closer inspection revealed another purple fringeless orchid about 4′ from the original patch. As I began looking around, I found four more orchids in flower. After doing my happy dance, I headed towards the creek to finish my walk. Approximately 40′ from the rest of the orchids, I came across one more orchid in flower. There are now fifteen orchids, twelve of them in flower, spread out approximately 100′ along a wet weather, shallow swale through our woods.
A slide show of fifteen purple fringeless orchids that I have located as of July 12, 2024.
Some Final Thoughts
I love Kentucky’s native orchid species. I was thrilled when I discovered the volunteer purple fringeless orchid in our woods. Now seeing a natural population growing and spreading, from the simple act of Alexander Walker hand pollinating the original volunteer, has been so gratifying. I will continue to closely observe and monitor these orchids. With twelve plants in flower, I fully expect to see several plants producing seed this year. With six plants outside of the fence I built, I will be able to see if my concerns about herbivory by deer were justified. If the plants outside of the fence are not browsed, I will remove the fence and let all of the orchids grow unprotected, and hopefully, increase in numbers. I will continue to remove invasive species that pop up. For a few more years, I will also remove any seriously aggressive native species that may cause problems for the orchids.
The conservation of this population of purple fringeless orchid is a small, successful step on our journey to restore a diverse, native woodland. It demonstrates that, given a chance, our native plants are resilient and can grow and thrive.
Purple Fringeless Orchid (Platanthera peramoena)
North American Orchid Conservation Center
“Platanthera peramoena, also called Purple Fringeless Orchid, has a limited distribution in the southeastern and central United States, from Missouri to New Jersey. It produces 2-5 spreading leaves along its stem, and bears an inflorescence of multiple, showy, pink or purple flowers. The labellum is deeply three lobed and usually slightly dentate (not fully fringed), although it is occasionally nearly entire; a prominent notch slits the central lobe of the labellum. It grows in moist forests, woodlands, meadows, and thickets, as well as in marshes and swamps. It appears to benefit from natural disturbances that reduce over head tree canopies and result in more light.
Platanthera peramoena is considered globally secure, although it is rare or vulnerable throughout most of its range. It can be distinguished from P. psycodes and P. grandiflora by its entire (unfringed) labellum.”
Biota of North America (BONAP)
Map showing the range of P. peramoena. Dark green are states where the species is native. Light green counties are locations where the species has been found growing in the wild. Yellow counties are locations where the species has been found growing in the wild and the species is rare in the state. Orange counties are counties where the species was once found and is now considered extirpated in the state.
“Platanthera peramoena (Gray) Gray
ALI: no HAB: 6,9, n/a, C, 4 ABU: g8?, s8, -4
This ranges from mid-Atlantic states to the eastern edge of the Ozarks and Ouachitas regions (K). In Ky. most records are from lowlands in thin swampy woods and associated openings with damp medium-acid soils. P. peramoena is virtually absent from landscapes with fertile soils that have been largely converted to agriculture, especially the Bluegrass region, except for a few old river terraces with exogenous alluvium (Bryant 1978, Meijer et. al. 1981). However, there are many records from se. Ind. and sw. Ohio in transitions from the Bluegrass to glaciated land (K). The type at GH is a coll.. of C.W. Short in 1835 from “wetlands about Louisville” (JEFF); MM also collected the species from JEFF in 1987.”