For this year’s Orchid Show, we’ve gathered stories about the most famous orchid of them all: the genus Vanilla. (Yes, vanilla is an orchid.) One unusual story comes from Ph.D. student Lynnaun Johnson, whose work in our doctoral program in Plant Biology and Conservation took him to Mexico, the native land of edible vanilla.
Last April, I ventured to Mexico as part of an international team investigating how cultivation practices influence the growth and health of the orchid Vanilla planifolia.
Vanilla planifolia produces the seedpods used to make vanilla, the spice used for flavoring desserts and beverages, and for providing wonderful aromas in candles, perfumes, and many other things. This collection trip would take me to vanilla’s native habitat of Mexico. All varieties of vanilla originated in Mexico, including those of Madagascar and Tahiti.
Vanilla cultivation
Tahitian vanilla is a hybrid of V. planifolia (shown) and V. odorata. Photo by H. Zell CC-BY-SA-3.0
While in Mexico, I visited three farms in the state of Veracruz and one in the state of Puebla. It was fascinating driving to these vanilla farms with my Mexican collaborators. It took us three days of traveling to complete our field collections. Each of the four farms had very different methods of growing V. planifolia. For instance, one of the farmers said he knew what his plants needed and thought growing his vanilla on concrete blocks was the best method. At another farm, the farmer brought decaying wood from a neighboring forest and used it as mulch for his vanilla plants that grew on living posts known as “tuteurs.” This was different from the other farmers who grew their vanilla on trees in the forest and wooden dead “tuteurs.”
Each of the plantations had different soil texture. At the last organic farm, the soil was compact and hard. At the farms that were in the forest, the soil appeared rich and softer. There is no way to quantify the terrestrial root growth, but I did note that the roots in the organic farms were longer and healthier, with some growing up to 4 or 5 feet when we dug the roots up from the soil.
At the Pantapec farm in the state of Puebla, Mexico, vanilla is cultivated in a highly managed environment.
By contrast, the vanilla grown at 1 de Mayo farm in the state of Veracruz, Mexico, is cultivated in a completely natural environment.
The benefits of fungi
Research on rare and endangered orchids usually focuses on finding fungi to help in the germination of orchids. We know that orchids will only germinate in nature using fungi. In addition, fungi living inside of plant leaves can benefit the plants’ health by preventing pathogens from growing. Also, bacteria living within the plants and fungi can be beneficial in the same way as the endophytic fungi. (Photo: V. planifolia tissue microscopy at 100x)
My part of the research project is to collect root samples from V. planifolia from each of these different farms to study the fungi and bacteria inhabiting this orchid. Currently, not much is known about the microbes (fungi and bacteria) that reside in orchid roots. Some fungi and bacteria can cause diseases. For example, with the appearance of a fungal pathogen such as Fusarium oxysporum, Mexican farmers can lose 67 percent of their crops when the Fusarium causes the rotting of the Vanilla’s stem and roots. On the other hand, there are beneficial fungi that inhabit roots, known as mycorrhizal fungi. These beneficial symbiotic fungi acquire mineral nutrients for the Vanilla, and sometimes receive carbon from the orchid in exchange. Although 90 percent of plant species have mycorrhizal fungi, and while we have a good understanding of mycorrhizal fungi of some of these relationships, relatively little is known about the mycorrhizal fungi of orchids, including V. planifolia. The reason for this is that isolating and growing the fungi and bacteria associated with orchid roots can be difficult, and some have never been grown outside of their host.
At each farm, I wanted to sample five individual plants of V. planifolia. Additionally, because of the lifestyle of this orchid, I also wanted to sample the above-ground roots (epiphytic) and the below-ground (terrestrial) roots in the soil. Using either a scissors or a scalpel, I cut small root samples and placed them into Ziploc bags. The vanilla plants are very precious to the farmers, and so a few were initially uncomfortable with our cutting off pieces, but ultimately they were very accommodating.
Epiphytic or terrestrial?
Typically, vanilla grows as a vine, with two types of roots: epiphytic roots (those that wrap around trees or other structures) and terrestrial (soil) roots. This is referred to as hemiepiphytic, because it starts in the ground and grows upward onto the tree’s bark. Many research papers suggest that epiphytic roots do not harbor many fungi, because these roots can photosynthesize, and do not need mutualistic fungus partners.
Back here at the Chicago Botanic Garden, I am in the process of evaluating the microbial community that lives in the root samples I collected. We are using a new technique called high-throughput sequencing that will enable me to evaluate the entire fungal and bacterial community within the orchid’s roots by using their DNA as a way to fingerprint the individual species of microbes. We are not certain how many species of fungi and bacteria we will find, but we predict that this method will give us a good picture of the fungal and bacterial community in these roots and if these communities differ among the different farming techniques. These data will be used to better understand how epiphytic orchids utilize mycorrhizal fungi and refine the best conditions to grow vanilla and prevent diseases in the plants.
This research trip was a delight, not only because of the samples that I collected, but also because I could learn more about how vanilla is grown and used. The farmers showed us how they cure and prepare the vanilla by fermenting it in the sun and before drying it thoroughly. I also tasted homemade “vanilla moonshine,” generously offered by the farmer’s wife. When visiting Papantla, I learned about the Aztec myth that explained how forbidden love created the sacred vanilla orchid. And of course, I was elated because I usually spend the majority of my research time in the lab. And here I was in the tropics, after spending the previous months facing the bitter Chicago 2014 winter.
Horticulturist Gabe Hutchison attaches orchids to their new habitat: the orchid trees in the Tropical Greenhouse.
Looking at it now, the winter of 2014 has not been an ideal year to tackle an in-depth and delicate project of this scale. A winter season with near record snowfall and record low temperatures has posed plenty of challenges in getting warmth-loving tropical orchids to the snowy, freezing Midwest, and securely into the Regenstein Center Greenhouses. Single-digit and sub-zero temperatures have been putting the Garden’s horticulture staff on heightened concern to protect these orchids in their various stages of buds and blooms. The transfer and well-being of more than 10,000 orchids has been a well-orchestrated undertaking shared by Garden staff (especially horticulturist Sharon Nejman) and the vendors who packed and sent the trucks.
A combination of metal cage and hazelnut (Corylus) tree branches creates the perfect framing to place an orchid display.
Beginning just a month ago, the Garden’s horticulture staff began a tear-down of Wonderland Express, immediately switching gears to the equally large endeavor of creating and setting up the Orchid Show. Existing Greenhouse beds have been modified to make room for impressive structures, and organic materials host epiphytic orchids of different genera. Presenting these impressive splashes of colorful orchids in a nontraditional display comes with some scalp-scratching challenges.
More than 10,000 orchids find homes on a variety of structures designed and fabricated by Garden staff.
Working closely with Orchid Show designer and horticulturist Brian Barker, I had the shared task of designating orchid choices based on the length of bloom life and needed care, while trying not to limit creativity and whimsy. My experience in maintaining private orchid collections for individuals and overseeing the care and aesthetics of three preexisting cork bark orchid “trees” in the Regenstein Greenhouses opened a role in the planning and installation of the show for me.
The entry to Nichols Hall transforms into an incredible tropical gateway.
In June 2012, when first presented with the challenge of building a new exhibition—an orchid show—we discovered logistical riddles we hadn’t considered being thrown at us. Along the way, new visions and ideas were presented, and have become focal points of the show during planning. Now we are here at the installation stage, with our materials, wondering,”How do I get hundreds of this particular orchid in these two or three colors to hang sideways or upside down over the visitors’ heads (sometimes way over), and keep the flowers happy?” Or, “How do we water a structure like this, and how do we do it efficiently?” Or, when we discover orchids are not happy in a location, how do we replace them quickly and in a way that doesn’t jeopardize the aesthetics of this visual centerpiece?
Teamwork is critical! Leah Pilon and Aysa Pogue gently weave orchid roots into a display frame.
Together, the horticulture staff is figuring out the solutions to these in-no-way-little challenges as they are presented, and in the process, admiring the great orchid creations that are coming together around us with pride. With every step, we are enjoying Brian Barker’s visions with the awe they deserve, knowing that in a few more days, we will be able to step back and appreciate our final creation and see it in the eyes of a Garden visitor.
Winter white blankets the ground outside, but inside, the Greenhouses are alive with jewel tones.
From the moment the public enters Nichols Hall, crossing through Joutras Gallery and the entrance into the Greenhouses, our goal is to present an experience of grandeur, a lush habitat of color, and a mix of curiosity and wonder.
We recently toured the Greenhouses with Boyce Tankersley, director of living plant documentation, to see what’s in bloom and take in the different climates visitors can enjoy.
In the Arid Greenhouse, we saw a number of species of aloe from South Africa just coming into bloom as well as cacti and succulents.
In the Tropical Greenhouse, we were surrounded by palms and cycads while we admired the many orchids in bloom. Tankersley pointed out the acanthus cultivar (Aphelandra sinclairiana ‘Panama Queen’) native to Panama and Costa Rica, as one of his favorites.
The Semitropical Greenhouse was filled with blooms like pinkball dombeya (Dombeya wallichii). Native to East Africa and Madagascar, the genus is a highly sought-after ornamental in USDA Zones 9 and warmer.
One of the rarest plants in our collections is Deppea splendens. Native to the mountains of western Mexico, this plant is extinct in the wild.
Visit our What’s in Bloom highlight page each week — twice a week during the summer bloom season — to learn more about the different plants in bloom. Then, come out to see them in person for their fragrance and the humidity of the warmer greenhouse climates.
Orchids are reaching their peak in The Greenhouses. The dragon mouth orchid is native from Guatemala to Panama, where the subspecies rosea is found. This dragon mouth orchid (Encyclia cordigera var. rosea) is in the Tropical Greenhouse, lower level, east epiphyte tree. The flower spikes can produce flowers for up to three months, and each of the flowers smells like chocolate. This species requires very bright light whether grown in greenhouses, on a windowsill, or under artificial lights. During the summer growing season it prefers a moist, humid growing environment, but in the winter the watering should be reduced and diurnal — the difference between night and day low temperatures — with temperature fluctuations of 10 degrees to initiate flower production. Learn more about what’s in bloom here. http://www.chicagobotanic.org/inbloom/highlight_archive/highlight_022812.php
Here at the Chicago Botanic Garden, we’re trying to make winter a little brighter and a little warmer. In The Greenhouses of the Regenstein Center, visitors can escape to a desert oasis and see aloes in bloom. They can feel the humidity of the tropics in the tropical greenhouse. They can even smell the fragrances of the temperate regions and see some interesting carnivorous plants! Sharon Nejman, Senior Horticulturist, takes us on a tour to show us what’s in bloom in each of the different climates we have recreated. Visit chicagobotanic.org/inbloom for more information on what’s in bloom at the Chicago Botanic Garden.
