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.

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

Wildfire. Flooding. Thirst. These issues can all be addressed through large-scale landscape restoration, according to speakers at the 2015 Janet Meakin Poor Research Symposium. Addressing a crowd of regional stewardship professionals and academics, as well as Conservation Land Management (CLM) and Research Experiences for Undergraduate (REU) interns at the Chicago Botanic Garden on June 12, they focused on solutions for ecological challenges.

The effects of strong conservation work are magnified when done on a large scale, they shared, and the theme of the day was how to magnify every step from seed-management procedures to restoration time frames and budgets to make the process as beneficial as possible. As mining, drilling, and similar industries move broadly across open lands in the United States and abroad, along with increasingly frequent and far-reaching extreme weather events, conservation practices must evolve with the times to keep pace.

PHOTO: Conservation and Land Management (CLM) interns measure species density in the field.

Conservation and Land Management (CLM) interns measure species density in the field.

As the CLM interns prepare to set off on a summer of hands-on restoration work across the United States, and potentially launch their careers shortly thereafter, these are critical issues for them to understand, according to Kay Havens, Ph.D., of the Chicago Botanic Garden, who organized the symposium. Many of the interns work in partnership with the Bureau of Land Management (BLM) on the ground in forestry, wildlife management, and habitat restoration, among others.

Fittingly, the first speaker of the day was Amy Leuders, the acting assistant director of BLM, who noted that the partnership with the Garden since 2001 has led to the training, hiring, and placement of more than 1,000 interns on federal lands. About 50 percent of those interns are later hired by a stewardship agency. “The Bureau of Land Management has had a long and successful partnership with the Chicago Botanic Garden…developing the next generation of land stewards,” she said.

In particular, she imparted to the audience the importance of developing a large scale national seed strategy, so that targeted plant seeds will be thoughtfully collected and preserved for future use. She cited examples of events in which seeds saved by chance allowed for the restoration of areas that later succumbed to natural disasters like wildfires and hurricanes. This new process would allow for seed saving to take place in a more proactive and calculated manner.

PHOTO: Seeds are collected at the Garden and stored in the Dixon National Tallgrass Prairie Seed Bank.

Collected seeds are stored in the Dixon National Tallgrass Prairie Seed Bank.

According to the second speaker, Kingsley Dixon, Ph.D., professor at Curtin University and the University of Western Australia, the current supply of wild seed cannot support global restoration demands. Innovations are helping to change that. Tools that process seeds into pellets or other small packets facilitate their successful mass delivery into recovering ecosystems, helping to achieve the level of seed performance seen in the agricultural sector. He noted that “Only by thinking at an industrial level of efficiency will ecological restoration be able to achieve the pace needed to protect and enhance natural resources.”

Drinking water quality can also be managed by restoration, said Joy Zedler of the University of Wisconsin-Madison. She shared examples of how restoration has been “scaled up” adaptively (learning while restoring) to benefit large areas. When it comes to managing water, she explained, it is essential to manage an entire watershed. One area of poor water quality will flow into every crevice in the system, for example. In the end, she explained, it is about safeguarding ecosystem services that human health and wellbeing depend on, from clean water to fresh air. “Our global society needs to redirect itself to achieve a sustainable future,” she said.

Brian Winter of the Nature Conservancy in Minnesota echoed her sentiments, as he ran through a real-life wetland restoration process for the audience. He emphasized that wetlands hold rainwater and are capable of preventing disastrous amounts of water from washing through nearby agricultural fields. The value of wetland restoration is immense and ongoing, he explained.

Conservation is in transition, explained speaker John Rogner of the U.S. Fish and Wildlife Service. Rogner discussed the steps involved in planning for a successful restoration, and the importance of landscape conservation cooperatives that can work together across states or even countries to identify and address issues in a given geographic area such as the Great Lakes watershed. He outlined an ongoing project to improve blockages in the Great Lakes system that impede fish migration. This can lead to a buildup of invasive plant species that create additional system blockages. A regional perspective and collaboration across entities is critical, he said. “It is absolutely essential that everyone have access to the same information to keep moving in the right direction,” added Rogner.

Issues that often fall to the side in planning are conceptual, according to James Aronson of the Missouri Botanical Garden. He urged the audience to pay attention to the economic side of their work by learning to speak and think in terms of renewable natural capital. Across land and ocean, natural capital can be restored to facilitate the flow of ecosystem services such as fresh air and clean water.

PHOTO: One of our greatest national resources and treasures: the Colorado River Basin.

One of our greatest national resources and treasures: the Colorado River Basin.

Lastly, Megan Haidet with Seeds of Success emphasized the importance of partnerships to meet the goals of the Bureau of Land Management’s National Seed Strategy for Rehabilitation and Restoration 2015–2020. She noted that increased coordination is vital to accelerate the pace and scale of restoration and provide native plant materials when and where they are needed.

The Garden’s CLM interns have now dispersed across the United States, where they will work for the next five months on public lands to put these lessons into action.

©2015 Chicago Botanic Garden and

Do you ever feel like trying to understand plant science research can be as daunting as deciphering a passage written in a foreign language?

As a budding plant scientist in the joint Chicago Botanic Garden/Northwestern University Ph.D. program, I find it exciting to pick through dense scientific text. Uncovering the meaning of a new acronym and learning new vocabulary can be thrilling, especially when decoding something new.

PHOTO: Kelly Ksiazek speaking in Sydney, Australia.

This past fall I spoke to a group of green infrastructure professionals in Sydney about the importance of urban biodiversity.

But the commonly used styles in scientific writing and presentation packed with language used to convey big topics in small spaces can be really off-putting to an audience of non-scientists. Many of us can conjure up a memory of a professor or teacher who seemed to like their subject matter but couldn’t convey the material in an interesting way. All of a sudden, science became boring.

Rather than struggling to learn this “foreign language,” many folks stop paying attention. Lack of scientific literacy, especially as it applies to plants, is a pity. Plants are all around us! They are so valuable to the entire planet. The very applicable field of botany shouldn’t be something that’s only discussed and understood in laboratories or scientific conferences—it should be for everyone.

This idea inspires me to try and bring my current botany research to a wide variety of people.

PHOTO: Ksiazek takes her presentation on the road to Pittsburgh.

I’ve had the chance to speak with many visitors to the Chicago Botanic Garden about my research, and typically bring some of my research supplies, as seen here from a trip to Pittsburgh.

PHOTO: Growing UP in the City: A Book About Green Roofs.

Writing and publishing a children’s book helps bring my research findings to kids all over the world.

For example, I recently realized that there are very few resources available to teach young students about the habitat where I currently collect most of my data: green roofs. While some of the methods I use for data collection and analysis can be quite complex, the motivations behind my work and some of the findings can be broken down into some basic ideas, applicable to students of all ages. So a fellow botanist and I wrote and produced Growing Up in the City: A Book About Green Roofs.

Our children’s activity book teaches youngsters about some of our research findings. The book follows a pair of native bumblebees through a city, where they guide the reader through engaging activities about the structure, environmental benefits, and motivations for building green roofs. At the end, readers even have the opportunity to ask their own research question and carry out a green roof research project of their own.

Interested in your own copy of our book? More information and a free digital download of the book are available at

PHOTO: Ksiazek presents her work to a girls' middle school.

Talking to 100-plus middle school girls about why it’s cool to be a botanist was a great experience!

The activity book is just one example of ways that plant scientists can engage with a broader audience and make their research findings more accessible. Some of the other activities that my colleagues here at the Chicago Botanic Garden and I have participated in include mentoring undergraduate and high school students, speaking to community organizations, creating lessons for schools and school groups, volunteering for summer programs, and maintaining a presence on the Internet through online mentoring, blogging, websites, and Twitter.

PHOTO: Ksiazek and an undergraduate student identify green roof plants.

Teaching undergraduate students how to identify plants on green roofs is one way of passing on my research knowledge.

PHOTO: Ksiazek discusses her research with a visitor to the PCSC.

My experiments on the green roof at the Plant Science Center are visible to everyone. Come take a look!

Here at the Garden, we scientists also have a unique variety of opportunities to share our science with the thousands of visitors who come to the beautiful Daniel F. and Ada L. Rice Plant Conservation Science Center. If you’ve never been to the Plant Science Center, you should definitely stop by the next time you’re at the Garden. You can see inside the laboratories where the other scientists and I collect some of our data. There are also a lot of interactive displays that aim to demystify plant science research and decode some of the “foreign language” that science speak can be. For a really interactive experience, come visit us on World Environment Day, Saturday, June 6, and talk to scientists directly. Bring your kids, bring your neighbors, and ask a botanist all those burning plant questions you have! We promise to only speak as much “science” as you want.

For more information about my research and science communication efforts, please visit my research blog, Kelly Ksiazek’s Botany in Action, and follow me on Twitter @GreenCityGal.

©2015 Chicago Botanic Garden and