Archives For plant science

Students in the Chicago Botanic Garden and Northwestern University Program in Plant Biology and Conservation were given a challenge: Write a short, clear explanation of a scientific concept that can be easily understood by non-scientists. Each week this spring, we’ll publish some of the results.

These brief explanations cover the topics of seed dormancy and germination, the role of fire in maintaining prairies, the evolution of roots, the Janzen-Connell model of tropical forest diversity, and more. Join us the next several weeks to see how our students met this challenge, and learn a bit of plant science too.


PHOTO: Alexandra Seglias at work in the field.Alexandra Seglias is a second-year master’s student in the Plant Biology and Conservation program at Northwestern University/The Chicago Botanic Garden. Her research focuses on the relationship between climate and dormancy and germination of Colorado Plateau native forb species. She hopes that the results of her research will help inform seed sourcing decisions in restoration projects.


PHOTO: A tiny oak sprouting from an acorn.

A tiny oak emerges from an acorn. Photo by Amphis (Own work) [CC BY-SA 3.0], via Wikimedia Commons


Dormancy and Germination

The seed is an essential life stage of a plant. Without seeds, flowers and trees would not exist. However, a seed doesn’t always live a nice, cozy life in the soil, and go on to produce a mature, healthy plant. Similar to Goldilocks, the conditions for growth of a seed should be “just right.” The charismatic acorn is just one type of seed, but it can be used here as an example. Mature acorns fall from the branches of a majestic oak and land on the ground below the mother tree. A thrifty squirrel may harvest one of these acorns and stash it away for safekeeping to eat as a snack at a later time. The squirrel, scatterbrained as he is, forgets many of his secret hiding places for his nuts, and the acorn has a chance at life. But it’s not quite smooth sailing from here for that little acorn.

Imagine trying to be your most productive in extreme drought, or during a blizzard. It would be impossible! Just as we have trouble in such inhospitable conditions, a seed also finds difficulty in remaining active, and as a result, it essentially goes into hibernation until conditions for growth are more suitable. Think of a bear going into hibernation as a way to explore seed dormancy. The acorn cozies up in the soil similar to the way a bear crawls into her den in the snowy winter and goes to sleep until spring comes along. As the snow melts, the bear stretches out her sore limbs and makes her way out into the bright world. The acorn feels just as good when that warmer weather comes about, and it too stretches. But rather than limbs, it stretches its fragile root out into the soil and begins the process of germination. This process allows the seed to develop into a tiny seedling — and perhaps eventually grow into a beautiful, magnificent oak tree.

Our scientists are studying seed germination in a changing climate. Learn how you can help efforts to help match plants to a changing ecosystem with the National Seed Strategy


©2016 Chicago Botanic Garden and my.chicagobotanic.org

Spike’s Teachable Moment

What was happening with Spike? Our scientists investigate.

Karen Z. —  August 30, 2015 — 6 Comments

What an amazing plant science moment occurred in the Semitropical Greenhouse this morning, as a fascinated crowd gathered to see what was happening with Spike, the titan arum.

On Saturday, it was determined that Spike had run out of the energy it needed to continue its bloom cycle. Spike is powered by energy from the sun, stored in its beach-ball-sized corm—a tuber-like underground structure. A tremendous amount of energy goes into producing the single, giant flower structure that a titan can send up in its first decade or so of life (Spike is about 12 years old).

Overheard: “I wish my biology teacher was here.”

As this week’s expected bloom time passed, our science and horticultural staff went into action. Spike wasn’t dying—but the flower structure had stopped maturing, and the spathe did not open. On Friday, Dr. Shannon Still, conservation scientist, and Tim Pollak, the floriculturist who had raised Spike from a seed, peeked inside the frilly spathe to check for pollen.

“If there had been pollen, it would have been all over my hand,” Still said. Pollen’s absence meant that the male and female flowers might not be fully developed. The possibility remained that pollen might still develop, even though the spathe would not open—and THAT led to the decision to remove the “frozen” spathe to see what was happening with the real flowers inside.

Overheard: “We were watching it every day. Every 20 minutes or so.”

First, Still assembled a working kit: scalpel, probes, test tubes, paintbrushes and a “scoopula” (to collect pollen).

At 10 a.m. today, staff gathered for the delicate procedure. Pollak and Still fist bumped…and the operation began. 

As Still began cutting just above the peduncle (stalk), the crowd grew quiet. Dr. Pat Herendeen, senior director, Systematics and Evolutionary Biology, narrated for the crowd. As the spathe started to come away from the towering spadix, the internal color started to be visible.

Left: a cross-section of the spathe reveals the cell structure inside. Right: close-up on the hundreds of male (top) and female (bottom) flowers inside Spike's spathe.

Left: A cross-section of the spathe reveals the cell structure inside. Right: A close-up of the hundreds of male (top) and female (bottom) flowers inside Spike’s spathe.

“The spathe feels a bit like cabbage leaves, with a rubbery texture,” Herendeen said. “The color inside varies from one plant to another in nature. It is dark maroon, the color of rotting meat, which is meant to attract the flies and beetles that are the plant’s natural pollinators.”

Pollak held the spathe steady as Still continued to free it from the stalk. With one last cut, it came free—and the crowd gasped as the inside of the spathe was unfurled and the true flowers at the base of the spadix were revealed—pale rows of bumpy-looking male flowers atop a strip of orange and brown female flowers.

Tim Pollak and Shannon Still make the first cut.

Left: Tim Pollak and Shannon Still make the first cut. Right: Tim Pollak reveals the spathe’s ravishing color.

Herendeen answered as questions flew: The male flowers do not appear to have produced pollen yet. Spike’s fabled scent is only detectable very close up to the spathe—much less apparent than it was earlier in the week.

Cameras focused in on the flower structure, as Still and Pollak carried the two large pieces of the cut-away spathe over to the crowd. Hands reached out for a touch; noses leaned in for a sniff. Spike’s spathe was set out on a gallery table so that everyone could touch and admire it before it begins to wilt.

Overheard: “Spike was the topic of dinner conversation with our two sons every night for the past week.”

While television camera crews stepped in for close-ups on the plant’s flowers, interviewers questioned the scientists: Where does the scent come from? (It’s believed that the tall appendix helps produce the scent, though scientists are also investigating the female flowers themselves.) Would Spike bloom again? (Probably, but the corm would have to recover first, by sending up an annual leaf for a few years to gather more energy.)

Cross-legged on the floor opposite Spike sat Chicago artist Heeyoung Kim, who sketched intently during the entire process. Her intricate pencil markings captured Spike’s pleats and tightly clustered flowers—the beginnings of a botanical illustration that could inform future scientists studying the titan arum’s beautiful structure for years to come.

We have been so thrilled with the intensity of interest in Spike—it’s not every day that crowds gather to watch a plant grow! We’ll continue to keep you posted about possible pollen development, our scientists’ thoughts about Spike’s arrested development, and on the progress of the eight other titan arums now growing in our production greenhouses. 

Left: what a great vibe! Right: Kris Jarantoski explains Spike's spathe to a young visitor.

Left: What a great vibe from the gathered crowd! Right: Kris Jarantoski, executive vice president and director, explains Spike’s spathe to a young visitor.

For more information please visit our titan arum page.

©2015 Chicago Botanic Garden and my.chicagobotanic.org

Popular culture moves in strange ways. Since the release of the eponymous movie, the idea of a “bucket list” has quickly become part of our modern vernacular.

My botanical bucket list includes plants like the ancient bristlecone pines of Nevada and the cobra-lilies of Northern California. Recently, in the Peruvian Amazon, I checked off my list the giant Amazonian waterlily. I’ve seen it many times before; it is grown all over the world. But coming across it in an Amazonian backwater, untended by people, is quite a different experience. 

PHOTO: Victoria amazonica, the giant Amazonian waterlily.

The giant Amazonian waterlily (Victoria amazonica), with its magnificent leaves beautifully arrayed like giant solar panels in the tropical sun

Plants like Amazonian waterlilies, bristlecone pines, and cobra-lilies have a presence. Even brief contemplation invokes a sense of wonder, and sometimes an emotional, even spiritual, connection. These charismatic plants are tangible expressions of the glory and mystery of nature. And paradoxically, that sense of mystery is undiminished by scientific understanding. As Einstein once said, “What I see in Nature is a magnificent structure that we can comprehend only very imperfectly, and that must fill a thinking person with a feeling of ‘humility’.” 

The Amazonian waterlily is one of the botanical wonders of the world, but look closely and every plant has its own mysterious life story full of evolutionary twists and turns. Whether in the garden, in the forest preserve, or along the roadside, even the most inconspicuous weed is a twig atop the gnarled and much-ramified tree of life. Every plant is a living expression of the vicissitudes of thousands, often millions, of years of history. 

PHOTO: Guest columnist and Garden board member Peter Crane, Ph.D.

Guest columnist and Garden board member Peter Crane, Ph.D.

Over the past three decades the evolutionary tree of plant life has come into clearer focus, as we have learned more about living plants, including about their genomes. We have also learned more about plants of the past by exploring their fossil record. There is still much that remains beyond our grasp, but scientists at the Chicago Botanic Garden are at the forefront of current research, including efforts to integrate information from fossils and living plants toward a more complete understanding of plant evolution. And viewing the world’s plants through an evolutionary lens only accentuates our sense of wonder. The leaves and the flowers of the Amazonian waterlily are massively increased in size and complexity compared to those of its diminutive precursors, which begs further questions about why and how such dramatic changes occurred. 

To borrow a phrase from Darwin, “There is grandeur in this view of life.” Such perspectives, rooted in deep history, emphasize the power and glory of evolution over vast spans of geologic time, as well as its remaining mysteries. In the face of rapid contemporary environmental change, they also underline the need for enlightened environmental management. Looking to the past to help us understand the present sharpens our view of the glories of nature. It also reminds us of our place in the world, and the value of humility as we together influence the future of our planet. 

Renowned botanist Sir Peter Crane is the Carl W. Knobloch, Jr. Dean, Yale University School of Forestry & Environmental Studies and former director of the Royal Botanic Gardens, Kew. Dr. Crane is also a life director of the board of the Chicago Botanic Garden. In 2014 Dr. Crane received the International Prize for Biology, administered by the Japan Society for the Promotion of Science, for his work on the evolutionary history of plants. The award, created in 1985, is one of the most prestigious in the field of biology.

This post is a reprint of an article by Sir Peter Crane, Ph.D. for the summer 2015 edition of Keep Growing, the member magazine of the Chicago Botanic Garden. ©2015 Chicago Botanic Garden and my.chicagobotanic.org

On any given day, the Chicago Botanic Garden’s science laboratories are bustling with activity. Some of the researchers are extracting DNA from leaves, analyzing soil samples, discussing how to restore degraded dunes—and talking about where they’re going to college. The young researchers are interns in the Garden’s College First program, studying field ecology and conservation science, and working side by side with scientists, horticulturists, and educators.

PHOTO: Orange-shirted middle schoolers examine palm trees and take data in the greenhouse.

Science First participants gather data in the Greenhouse.

PHOTO: Two high school girls wearing blue "College First" tshirts and latex gloves examine samples in the lab.

Two College First participants work on analyzing samples in the Garden’s plant science labs.

The Science Career Continuum consists of five programs:

  • Science First, a four-week enrichment program for students in grades 8 through 10.
  • College First, an eight-week summer internship for high school juniors and seniors with monthly meetings during the school year.
  • Research Experiences for Undergraduates (REU), a ten-week summer research-based science internship supervised by a Garden scientist and funded through a National Science Foundation grant. In 2014, three College First graduates will participate.
  • Conservation and Land Management (CLM) internship, offered through the Department of the Interior’s Bureau of Land Management and held in 13 western states.
  • Graduate programs in plant biology and conservation, offered jointly with Northwestern University for master’s degree and doctoral students.

The program is part of the Science Career Continuum, which is aimed at training the next generation of dedicated land stewards and conservation scientists. The Continuum engages Chicago Public Schools students from diverse backgrounds in meaningful scientific research and mentoring programs from middle school through college and beyond. “Each level of the Continuum challenges students to improve their science skills, building on what was learned at the previous level and preparing them for the next,” said Kathy Johnson, director of teacher and student programs.

College First is a paid eight-week summer internship for up to 20 qualified students. Isobel Araujo, a senior at Whitney Young High School in Chicago, attended the College First program in 2011 and 2012. As part of the program, she did research on orchids and learned how to estimate budgets to fix hypothetical ecological problems. “It was definitely challenging, but it was awesome,” said Araujo, who plans to major in environmental studies.

During the school year, College First students also attend monthly meetings that help them select colleges, complete applications, and find financial aid to continue their education. More than 94 percent of College First graduates attend two- or four-year colleges, and many are the first in their family to attend college. Three students, including Robert Harris III, received full scholarships to universities beginning in fall 2013.

Harris is a freshman at Carleton College in Northfield, Minnesota. As a junior and senior at Lane Tech High School in Chicago, he made a three-hour daily round-trip commute to the Garden for the College First program. During his internship, he learned to extract plant DNA and study genetic markers in the Artocarpus genus, which includes breadfruit and jackfruit. Harris said the program was a great experience. “You get out of the city and experience nature close up,” he said. “The Garden itself is one big laboratory, and it was a lot more hands-on than in high school.”

PHOTO: An intern carries a quiver full of marking flags, and takes notes on her clipboard.

Science First and College First programs lead into other graduate and postgraduate programs. Visit chicagobotanic.org/research/training to find information on these programs.

PHOTO: A group of about 50 people pose at the end of the Serpentine Bridge.

Conservation and Land Management (CLM) postgraduate interns for 2013 pose for a group photo at the Garden. Visit clminternship.org to find out more about this program.

Because of funding restrictions, enrollment for the Continuum programs are limited to students from Chicago Public Schools. For more information, visit chicagobotanic.org/ctl/teacher_students or call (847) 835-6871.


This post was adapted from an article by Nina Koziol that appeared in the spring 2014 edition of Keep Growing, the member magazine of the Chicago Botanic Garden.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

The Conservation and Land Management Program (CLM) is in its 10th year in 2011. Each year, the Chicago Botanic Garden places 75-90 interns with Federal biologists working primarily in twelve western states including Alaska, Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. Interns work on botany- or wildlife-focused projects for five months. Most of the time is spent doing field work and gaining hands-on experience working for a federal agency. Applications for the 2011 program are now being accepted. Visit www.clminternship.org to apply.