Archives For Plant Science & Conservation

Conserving plants is one of the most significant challenges of our time—and a major focus at the Chicago Botanic Garden. From studying soil to banking seeds, from restoring habitats and protecting endangered plant species to developing new ones, Garden scientists are fighting plant extinction, pollution, and climate change through diverse and exciting research.

The Critical Search for a Plant

Chicago Botanic Garden provides rare plant for toxin testing

Boyce Tankersley —  November 13, 2015 — 5 Comments

The clock was ticking—a little girl was seriously ill—when I got the call for help. A Denver hospital needed living tissue from Thujopsis dolabrata or any of its cultivars within 24 hours to determine if the plant was the cause of the girl’s life-threatening allergic reaction.

Don’t call us first! Call the U.S. Poison Control Center at (800) 222-1222. If you need help identifying a plant to determine if it’s poisonous—and it’s not an emergency—try our Plant Information Service at (847) 835-0972. Please bring in a live plant sample for an accurate identification.

The girl had been flown in from Japan to be treated at the hospital, National Jewish Health. After I got the call, I looked into the hospital, which is known worldwide for treating patients with respiratory, immune, and related disorders. In the girl’s case, the doctors apparently had a list of potential allergens they were testing, including Thujopsis, a rare evergreen shrub that is native to Japan.

A hospital official began the search for the plant with a colleague of mine at the Denver Botanic Gardens. My colleague met the girl’s grandmother, who showed her a picture of the patient’s red and inflamed face. When my colleague couldn’t help, she checked around and found via the Chicago Botanic Garden’s free smartphone app, GardenGuide, that we have the plant, commonly known as hiba arborvitae.

While the call came out of the blue—in my 17 years at the Garden, I’ve never fielded such a request—this type of emergency was not new to me. I used to be in charge of landscaping at the University of Texas Medical Branch in Galveston, and occasionally supplied plant samples from the campus gardens to the Texas Poison Control Center. Now, as the Garden’s director of living plant documentation, the response just kicked in.

It’s always a good idea to be aware of toxins in your home. The ASPCA keeps a list of houseplants that are toxic to pets; for a list of commonly available houseplants toxic to humans, check out this most common poisonous houseplants fact sheet from the New York Botanical Garden.

PHOTO: Thujopsis dolabrata 'Variegata'.

Thujopsis dolabrata ‘Variegata’

In the Garden’s production nursery, I snipped a branch from two different cultivars of Thujopsis. Within three hours of receiving the request, I had dropped the samples off at FedEx on the way home.

As it turned out, Thujopsis did appear to be the culprit, and the hospital is continuing to test the girl’s blood samples with extracts from the Thujopsis to determine what constituents are causing the allergic reaction (the same constituents can be found in related species, so the search to identify other potential sources is prudent). Meanwhile, the girl responded quickly to emergency treatment, was stabilized, and returned to Japan.

While public gardens and other outdoor spaces are often recognized for their mental health benefits, this incident reminded me of the fact that botanic gardens have made important contributions to the physical well-being of people in need.

For more than 450 years, botanic gardens have collected and housed plants from throughout the world for the public good, from medicinal plants in the sixteenth century to food crops used to expand and improve people’s diets (like potatoes, tomatoes, and corn introduced to Europe from the New World, and global economic plants like tea and cocoa). I’m proud to be a part of this history. 

©2015 Chicago Botanic Garden and

Capturing the Value of Wild Plants

Undercover Science

Julianne Beck —  October 11, 2015 — 2 Comments

Maps had been followed, clues tracked, and early this summer the fortune was found.

Standing on the far side of a hummock swamp in Delhaas Woods in Bristol, Pennsylvania, Andrew Bunting had located a unique magnolia tree population on the edge of fading away. He had discovered the treasure he set out to find. Often, this is where the story ends. But when the prize is an elusive plant sought by scientists nationwide, this is where the story begins.

PHOTO: Andrew Bunting collecting sweet bay magnolia samples in Delhaas Woods, Bucks County, Pennsylvania.

Andrew Bunting collecting sweetbay magnolia samples in Delhaas Woods, Bucks County, Pennsylvania.

Bunting, the assistant director and director of plant collections at the Chicago Botanic Garden, was on day three of a nine-day adventure across the East Coast to collect northern populations of Magnolia virginiana var. virginiana L.

Bunting welcomes any opportunity to stroll the Garden campus. “I like all the Gardens, of course, but there are a few favorites,” he admitted. “Part of me likes horticulture and part of me likes the scientific evaluation side of things.” He often stops through the Heritage Garden with a nod to statue of Carolus Linnaeus and the Bernice E. Lavin Plant Evaluation Garden.

After locating a group of trees in Delhaas Woods, he and his team took cuttings from new growth and packed them into their bags. The murky waters that now stood between them and a successful exit from the overgrown site were deep and dangerous, and wading out was not an option. They had no choice but to leap between hummocks—floating islands—of knotted blueberry vines, wild roses, and other invasive plants to reach stable ground.

It’s all in a day’s work for Bunting, who has gone on wild plant-collecting trips around the country and world during his career. Days after returning home, he explained that this adventure was no more tame than those in tropical jungles. However, the importance of this collection made it all worthwhile. The target species, commonly called sweetbay magnolia, is generally underrepresented in living collections and arboreta. That means that if it is lost in the wild due to extreme weather or other threats, there is no backup. It could be gone for good.

PHOTO: A sweetbay magnolia tree stands out in Delhaas Woods, Bucks County, Pennsylvania.

A sweetbay magnolia tree stands out in Delhaas Woods, Bucks County, Pennsylvania.

By taking plant samples from the field, he and his team hope to grow new generations of sweetbay magnolia plants that can be safely maintained in secure locations long term and used to study and potentially boost the wild populations in the future.

The success of the trip required more than one stop. The team visited multiple locations, collecting from several plant populations across the northern range of the species. Their goal was to collect trees with novel traits, or genes, which would be beneficial for future breeding.

When the team navigated the swamp, their spirits were still high from an especially unique collection they made the day before in the Michaux State Forest, about 125 miles west of Philadelphia. There, they had carefully taken cuttings from a population of state-threatened magnolias that grows far from any other. “I’m hopeful that some of our work may lead to help figure out why that population is where it is,” remarked Bunting, who theorized that the population may have had a broader range millions of years ago and retracted to the coastal plain. He hopes that future DNA tests of the samples will provide answers by clarifying genetic similarities and differences between this and other populations they collected.

Moving into New Jersey, he and his team next gathered additional cuttings. Working closely with project partner Joe Rothleutner, tree and shrub breeder at the Morton Arboretum, and other local experts who joined them along the way, Bunting assembled a detailed logbook to accompany the physical samples.

PHOTO: Magnolia virginiana var. virginiana L. in Michaux State Forest, Pennsylvania.

Magnolia virginiana var. virginiana L. in Michaux State Forest, Pennsylvania.

At every collection location, each team member played a specific role to capture information about the site; from the type of soil to the slope of the land to a description of the local ecosystem, and a list of associated plants. At each site, two 10-inch plant samples, ideally with forming fruits and/or flowers, were pressed between cardboard and labeled for future storage in a herbarium. Other samples were packaged for propagation. The collection project was funded by the U.S. Forest Service and American Public Gardens Association (APGA).

The challenges along the way made every discovery that much sweeter. “What’s nice is you all kind of bring your own expertise and experiences and figure out how to navigate the areas and how to extricate yourself from the areas,” said Bunting. “What’s great about the collecting trips is that you can do a lot of front-end research but there are always surprises,” he added.

On the final leg of the journey, the team members found themselves wearing knee-high boots in the thigh-high waters of a sphagnum swamp in Staten Island. Sinking in deeper with every step, they waded through, only to find no evidence of magnolias. Swatting away mosquitoes and dodging deer ticks, they navigated a thick understory of sharp phragmites reeds and Japanese knotweed to make their escape.

PHOTO: An extended telescopic pole is used to take cuttings of the current season’s plant growth.

An extended telescopic pole is used to take cuttings of the current season’s plant growth.

In all, they returned home with representatives from nine populations and 850 unique cuttings.

Many of the species on display at the Garden today were once such wild treasures, explained Bunting, who, after years working for esteemed institutions across the country, returned to the Garden this spring in part to re-establish a collection program.

Records of wild collected plants’ origins hold a value that extends beyond dollars. Details of when and where each collected plant was gathered are stored in the Garden’s plant records database. Those pieces of information build a story for each specimen. The stories provide guidelines for conservation scientists who may need to propagate the species should a natural habitat be temporarily lost, and for breeders who may wish to develop a new, hardy species to better endure harsher winters, for example.

Many other species of plants are preserved when their seeds are collected and placed in seed banks. However, for some, such as the sweet bay magnolias, timing the seed collection and storing them long term is difficult, so the cuttings are the best approach.

Mapping the Journey

Bunting is building a ten-year collection plan that he expects will take Garden experts to one or two national and one international location(s) each year. “I would like this new plant-collecting program to really think about filling a lot of needs at the Garden, whether it’s evaluation, breeding, plant conservation, adding to our horticulture collection, or maybe interpretation and education,” he said. Collections will take place in similar climates to the Chicago area.

PHOTO: In Delhaas Woods, cuttings are labeled and pressed between pieces of cardboard for transportation to a herbarium for further processing and storage.

In Delhaas Woods, cuttings are labeled and pressed between pieces of cardboard for transportation to a herbarium for further processing and storage.

Plants selected for collection may be representative of a different country, or they may expand the Garden’s representation of a specific species, for example. Working with other Garden scientists, graduate students, and the Morton Arboretum, he is also building in steps to ensure that species are screened in advance so that no potentially invasive species are collected.

“There are lots of parameters and variables that will evolve over time and also partnerships,” he said. The collecting trips will be done with a consortium of institutions from across the country. Results will be shared and tracked among them, and stored at the herbarium at the U.S. National Arboretum in Washington, D.C. Many will also remain long term at the Garden or other similar institutions. “We do want to fill in gaps (in the Garden’s collection), but we also want to add diversity,” said Bunting.

Sweet bay magnolia trees in a New Jersey state forest

Sweetbay magnolia trees in a New Jersey state forest

Over the next several months, Rothleutner will work to propagate the recent sweetbay magnolia cuttings. They will then be dispersed among selected gardens, including several that together hold a full representation of magnolia species from the United States and that are coordinated by the APGA. Plants will also be cultivated at the Chicago Botanic Garden.

©2015 Chicago Botanic Garden and

I scratch my head and wipe the sweat from my brow. One of my summer interns found a little plant, under a bunch of big plants, and we thought for a second it might be the same as the big plants, but it is definitely different. It’s our first field day. We don’t know what this plant is called, and it’s a hot and humid summer day in Chicago, and we have been searching through our identification guidebooks for what seems like forever. “Is it this one?” we ask each other, pointing to pictures in the book where the leaves kinda sorta look like our little plant. Finally, we flip through the book one last time, and it seems to open all on its own to the right place. It’s called water horehound (Lycopus americanus). We cheer! Now that we know this little plant’s name, we start to see it everywhere.

PHOTO: Poring over a specimen in the field.

Poring over a specimen in the field

I’ve been working all summer with a fresh-faced team of undergraduate interns to quantify plant community biodiversity (i.e. identify and count plants) in restored prairies around Chicago. Some of our sites have been right by the lake, some have been in community parks, some in forest preserves, and one in what seemed to be a drainage ditch. So far, we have identified more than 200 plant species.

Biodiversity is all around us. And I’m not just talking about in the tropical rainforest or a coral reef, though there are many species there, too. Even in the temperate zone, even in a park, and probably even in your backyard, there are many species. A species is defined as a group of organisms that can breed with one another. While most people would feel comfortable declaring that an elephant is different from a carp, an oak tree, or a shiitake, there are often much more subtle distinctions that can signify that organisms belong to different species. To humans trying to identify plants, the distinction between two species could be as minute as whether the leaf hairs are hooked or straight. Seeing species is hard but worthwhile. It will help you develop keen observation skills, and (I hope!) an appreciation of the world around you.

PHOTO: Dodecatheon meadia.

Shooting star (Dodecatheon meadia) is a distinctive early flowering species of the prairie. Photo by Jessica Riebkes

Before we can identify what a species is, we first have to determine that it is something different from the other surrounding plants. We tend to look at plants as a bunch of green stuff, not always recognizing the diversity present even in seemingly mundane habitats. We call this phenomenon “plant blindness,” the tendency to see plants as background, and not as unique organisms. My Ph.D. advisor said I should call our inability to recognize differences between species, “species blindness” (The only other reference I could find for species blindness was in Rutgers University Professor Lena Struwe’s bioblitz project).

Recognizing differences among species is only the first hurdle. Then, you have to identify them. The identification can be confounded in many ways, like the issue of timing. Some species may be distinctive at maturity but can remain a mystery at other times. Take rattlesnake master (Eryngium yuccifolium). There is no mistaking the master when it’s flowering. The flowers are small, green and white, but are contained within a spiky ball of a flowering head. The leaves are thick, pointy, and spear-like, prickles sticking out all along the edges. But when the mighty rattlesnake master pokes out of the ground in the spring, you would definitely mistake it for a grass; there are no flowers, no spiky balls, no spears. The only way to know it isn’t a grass is to observe the sparse, puny prickles just starting out.

PHOTO: Rattlesnake master (Eryngium yuccifolium) with a co-occuring species.

The distinctive rattlesnake master (Eryngium yuccifolium with co-occuring species. How many can you spot?

And while we’re at it, let’s talk about grass. (No, no I am not talking about marijuana.) Botanist Chris Martine already addressed that in his essay, “I am a botanist, and no, I don’t grow marijuana.”) I just mean grass, the stringy green stuff that grows out of the ground. This demonstrates another hurdle to combating species blindness: the sheer number of species out there. Guess how many species of grass there are. Go ahead, guess. The Royal Botanic Gardens, Kew keeps a database of grasses called, of course, GrassBase. Currently, GrassBase includes 11,313 different species of grass. Grass is actually a plant family, containing many different species (please see this amazing rap if you need a refresher on biological classification). As you can figure out by exploring an overgrown park, an abandoned field, or my favorite place to study grass, a prairie, there are grasses that are incredibly distinctive. Some have seedheads that smell like popcorn! Sometimes, though, the grass isn’t blooming (grasses are flowering plants, by the way), and you end up pulling back leaf after leaf trying to find a ligule to help with the identification. A ligule is what’s found where a grass leaf blade meets the stem. The ligule can be rigid or floppy, membranous, or hairy, or totally absent. Once you know that the ligule exists, you might try to find it on any and all grasses you pass (I do!).

Once you’ve found a distinct species, how do you figure out its name? We budding botanists have a few tricks. We search through field guides so many times that we memorize the pages for certain families. We spend a lot of time looking at the glossary of our field guides, trying to remember the meaning of botanical terms like panicle, petiole, connate, cordate, corolla, and cyme. We use multiple senses. We are known to crush leaves and breathe deep, searching for the piney smell of a goldenrod, the freshness of a mountain mint, or the musk of bee balm. We are almost obsessive about our rubbing of leaves to distinguish new textures. And we hunt for tiny clues (often with a hand lens) like a line of hairs down a stem or a gland at the base of a hair on the edge of a leaf blade. We value the time we get to spend in the field or the lab with expert botanists that put our identification skills to shame. And when all else fails, we post to Twitter or Facebook botany groups and someone always knows.

PHOTO: Becky Barak in the field.

The best part of the job—doing research in the field!

I’m asking you to combat species blindness by working hard to notice species. Dig a little deeper, look a little closer. If you’re out with children, challenge them to find as many different species as they can. At first glance, it may seem like everything is the same, but with careful observation, the species will begin to show themselves. Look at all parts of the plant. Flowers sometimes get all the love, but stems and leaves and fruits and seeds can hold the keys to identification. Plants are a good place to start because they are known to stay in one place, but the same patterns apply to all living things. Biological diversity is out there; you just need to know how to look.

©2015 Chicago Botanic Garden and

The Sky’s the Limit

Results (and Surprises) from the Green Roof

Richard Hawke —  July 20, 2015 — Leave a comment

When the Green Roof Garden was first planted in 2009, everything we knew about long-term rooftop gardening was theoretical. Which plants would live more than one year on the roof? No one knew for sure. Were native plants better to plant than non-natives? Unknown. What about soil depth, extreme weather, pests, diseases? The list of questions was long.

Download An Evaluation Study of Plants for Use on Green Roofs here.

PHOTO: The Roof Garden at the Chicago Botanic Garden Plant Conservation Science Center.

Download the results of this 5-year study. Click here.

Today, after five years of watching, waiting, documenting, and evaluating, we now have actual data to guide us—and others—on the ever-more-popular topic of green roofs! I’ve just published the Plant Evaluation Notes from our research—the first national plant evaluation study of its kind.

Among the data are a few surprises.

The biggest surprise may seem the most obvious—it’s that the green roof survived as well as it did!

I was blown away by the survival rates among plants, and by the fact that so many of them thrived and even excelled in such a challenging landscape. Of the more than 40,000 plants that we installed on both roofs, 30,568 of them were still alive in 2014. Just 14% of the 216 taxa died—that’s a pretty good success rate when you consider rooftop conditions. In fact, adaptability was one of the main criteria that we evaluated each plant on. Here’s the five-point list:

  • Adaptability (to hot/cold, dry, windy conditions, plus shallow soils)
  • Pests/diseases
  • Winter hardiness
  • Non-weediness
  • Ornamental beauty

Other surprises? Definitely the wild white indigo (Baptisia alba var. alba). Although I didn’t expect it to fail, I also didn’t expect it to be as large and vigorous as it has become. By year five, it was nearly three feet tall, with dramatic spires of white flowers. Meadow blazing star (Liatris ligulistylis) was in the same elegant category. But the absolute standout was prairie dropseed (Sporobolus heterolepis). It looked good all year, at all soil depths, and the fragrant flowers made the roof smell like popcorn in August and September.

PHOTO: Antennaria dioica.

Antennaria dioica

PHOTO: Baptisia alba var. alba.

Baptisia alba var. alba

PHOTO: Phlox subulata 'Emerald Blue'.

Phlox subulata ‘Emerald Blue’

PHOTO: View of the Green Roof Garden from above.

The Green Roof Garden today: a tapestry of plant life

It also surprised me that some of the drought-tolerant plants like sulfur flower (Eriogonum umbellatum), tufted fleabane (Erigeron caespitosa), and long-petaled lewisia (Lewisia longipetala ‘Little Plum’) didn’t do better on the green roof. Same goes for sundial lupine (Lupinus perennis). In a broader sense, I’m disappointed that we haven’t had greater success with plants in the shallowest, 4-inch soil depth. It’s the most challenging area on the green roof, so we’ll strive to add more types of plants to this trial area in the coming years.

PHOTO: Richard Hawke, Plant Evaluation Manager.

Monitoring plants in the field

Top 10 starstarstarstarstar Performers
on the Green Roof

  1. Pussytoes (Antennaria dioica)
  2. Dwarf calamint (Calamintha nepeta ssp. nepeta)
  3. Juniper ‘Viridis’ (Juniperus chinensis var. sargentii ‘Viridis’)
  4. Creeping phlox ‘Emerald Blue’ (Phlox subulata ‘Emerald Blue’)
  5. Creeping phlox ‘Apple Blossom’ (Phlox subulata ‘Apple Blossom’)
  6. Creeping phlox ‘Snowflake’ (Phlox subulata ‘Snowflake’)
  7. Aromatic sumac ‘Gro-Low’ (Rhus aromatica ‘Gro-Low’)
  8. Prairie dropseed (Sporobolus heterolepis)
  9. Prairie dropseed ‘Tara’ (Sporobolus heterolepis ‘Tara’)
  10. The 69 other plants that got four-star ratings (good)! 


What else is coming to the Green Roof Garden?

We’ll bring in a new set of plants (both native and non-native) to be evaluated and increase the replication of trials in 4-, 6- and 8-inch soil depths. Our goal is to compile a broad list of proven plants so that anyone—businesses, architects, governmental groups, and residential homeowners—has the information they need to grow a green roof. The sky’s the limit!

Visit the Green Roof Garden at the Daniel F. and Ada L. Rice Plant Conservation Center—open ‘til 9 p.m. all summer. The garden has two halves: the Ellis Goodman Family Foundation Green Roof Garden South and the Josephine P. & John J. Louis Foundation Green Roof Garden North.

©2015 Chicago Botanic Garden and

Embracing Trees for Our Future

Undercover Science

Julianne Beck —  July 13, 2015 — Leave a comment

If you spot a Chicago Botanic Garden volunteer wrapping their arms around a tree trunk this summer, don’t be surprised—what looks like a loving hug is actually a scientific measurement in process.

Using a specially designed tape measure, volunteers are recording the diameter of each tree before calculating the amount of carbon dioxide it stores. The study, launched by the Living Plant Documentation department five years ago, records the amount of the pervasive greenhouse gas stored by the Garden’s trees. The research team is interested in determining which trees are able to hold the most carbon for the longest amount of time.

PHOTO: Boyce Tankersley is researching the trees' response to increased carbon in the atmosphere, using data such as the growth rate of the particular tree species.

Boyce Tankersley and volunteers measure the diameter of each tree on the Garden campus.

The Tall and Short of It

It is one of the first such studies underway in a botanic garden setting. “We know carbon is increasing but we don’t have the numbers on how much carbon is being locked up by the urban forest,” said Boyce Tankersley, director of the Living Plant Documentation department. “This is where the Garden can play a role.”

Although similar studies have been completed by the lumber industry and others, it is important to understand how increased levels of carbon dioxide in the atmosphere are mitigated by cultivated trees, explained Tankersley. It’s also essential to document how those trees fare long term in evolving conditions.

The Garden has an especially diverse number of taxa, Tankersley said, positioning it perfectly to document how numerous species behave in locations from the McDonald Woods to the English Walled Garden to the parking lot. “The Garden is among the first to look at the trees in a Garden setting and at the diversity of taxa,” said Tankersley. “That’s a piece we’d like to shed more light on.”

This summer marks the second time the trees have been measured since the original data was gathered in the first year. Measurements will continue to be taken for another 15 to 20 years.

“We hope, when the data is analyzed, to be able to identify not only the trees that are best but the Garden settings that support their efforts in this regard,” anticipated Tankersley.

PHOTO: Tree canopy.

The Living Plant Documentation department is calculating the amount of carbon dioxide stored in each of the Garden’s trees.

Deep in the Woods

Trees are lauded for coming to our rescue in the face of climate change, but scientists have learned that these strapping heroes may not be infallible. “One thing we are looking for is the influence of carbon on the growth rate,” said Tankersley. His research team is paying close attention to the trees’ response to increased carbon levels in our atmosphere.

According to Tankersley, it has been documented that trees are growing more quickly than they have in the past, which comes with positive and negative repercussions. “Trees are providing an environmental service in a major way by absorbing carbon, but there’s a point of diminishing returns,” he explained. The wood of a fast-growing tree is softer, for example, which has a negative impact on the lumber industry, he explained. In addition, “with an increased growth rate, you also get increased susceptibility to insects and diseases.”

The concern underscores the need to observe the Garden’s trees for many years to take all such factors into consideration.

In addition, the team is watching the impact of weather on the trees, and taking dry spells or rainy periods, for example, into account when documenting tree growth over a given time frame. The Garden hosts a National Weather Service monitor on-site, which allows for weather-related calculations to be even more precise.

The Zipline

When the measurement phase of the study is complete, Tankersley plans to provide the data to a doctoral student in the Garden’s joint degree program with Northwestern University for formal analysis. “My take-home would be a list of the six best trees, perennials, and shrubs for sequestering carbon in the landscape in Chicago,” he said.

“We expect to find that trees like oaks, elms, and hickories—trees that are long-lived—provide a greater environmental service in this regard,” he added.

For homeowners who would like to assist with the issue now rather than wait for the final analysis, he suggests that they begin planting longer-lived trees. It may help mitigate, or reduce, the amount of carbon in the air and resulting climate change impacts such as extreme weather.

Our 2013 adaptive planting study carefully selected 60 suitable trees to plant for future generations. View the full list of suggested trees here.
PHOTO: Fastigiate English Oak acorns (Quercus robur).

It takes more than one year for the Garden volunteers to check the diameter of the 13,493 trees on-site, and enter the estimated carbon storage into a specialized database. The calculations are made using a formula developed by the U.S. Forest Service, said Tankersley.

The technique of measuring existing trees and planning for new plantings is something Tankersley hopes will have broad impact. He has already shared his process with countries in Africa through The Eden Projects and in China in an effort to help governments replace denuded forests there.

Tankersley is hopeful about the long-term implications of the study. After all, he said, when pioneers first came to the United States, they found oak trees that were about 300 years old, and had been providing benefits such as carbon sequestration for all of that time. Many of those hard-working, long-lived species have been a key part of our natural heritage since the beginning. By embracing the issue now, Tankersley and team have cleared the way for trees and their vital functions to endure.

©2015 Chicago Botanic Garden and