Exploring the science of plants, from the field to the lab

Archive: April 2015

Transplants: New Jersey Lichens Find New Home at NYBG

Posted in Interesting Plant Stories on April 30, 2015 by Science Talk

Jessica L. Allen is a graduate student at the Commodore Mathew Perry Graduate Studies Program, and James C. Lendemer, Ph.D., is an Assistant Curator at the Institute of Systematic Botany, both at The New York Botanical Garden. Lichens are their primary research interest.


This composite image shows, on the left,  a lichen-covered tree in a healthy forest in the Black Mountains of North Carolina and, on the right, how most trees in New York City look.
This composite image shows, on the left, a lichen-covered tree in a healthy forest in the Black Mountains of North Carolina and, on the right, how most trees in New York City look.

Most trees and rocks in New York City look naked, while trees in wilder parts of the United States wear a vibrant, colorful coat. What causes that? It’s because after centuries of changes to the environment, many lichens have been pushed from our urban or suburban landscapes and into the wilderness.

Lichens are fungi that, in addition to forming beautiful mosaics on trees and rocks, are critical to maintaining healthy environments. Unfortunately they are also extremely sensitive to air pollution and disturbance. That is why if you grew up in New York, and many other cities, you might think that bare trees and rocks are normal.

The good news is that, like the oysters that are slowly returning to New York harbor, there are more lichens in New York City now than there were 30 years ago. Yet there are still hundreds of species that were once found in the metropolitan area and are no longer here. We decided to investigate whether or not more lichens could survive in the city if we just gave them a little help getting here.

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Digitizing in the Dominican Republic

Posted in From the Field, Travelogue on April 23, 2015 by Stephen Gottschalk

Stephen Gottschalk, a former Project Coordinator for the William and Lynda Steere Herbarium, is now a graduate student in the Commodore Matthew Perry Graduate Studies Program at The New York Botanical Garden.


Stephen Gottschalk field books Science Talk Herbarium
The NYBG team at work in the Dominican Republic

Though many botanists specialize in Caribbean flora, few have so thoroughly documented the plant life of a single island, especially a large one, as has Thomas Zanoni, Ph.D., who lived and worked in the Dominican Republic for 13 years. His collections number in the tens of thousands and come from nearly every corner of Hispaniola, which comprises the countries of Haiti and the Dominican Republic.

Last year, my colleagues Stella Sylva and Brandy Watts and I traveled to the Dominican Republic to work on a project at the Dr. Rafael M. Moscoso National Botanical Garden (Jardín Botánico Nacional Dr. Rafael M. Moscoso) in Santo Domingo. Our purpose was to image the field books of Dr. Zanoni.

Making a collection as large as Dr. Zanoni’s digitally available to botanists across the globe is challenging. If one person were to work 40 hours a week typing out the information on each of his specimen labels, the job would likely take more than a year. Of course, that doesn’t include the time it would take to first find each of Dr. Zanoni’s 30,000-plus specimens, which are dispersed throughout not only our 7.4-million-specimen William and Lynda Steere Herbarium but also herbaria in other countries.

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Learning About Lichens: A New Guide to this Important but Overlooked Group From NYBG Press

Posted in Books: Past and Present on April 20, 2015 by Stevenson Swanson

Stevenson Swanson is the Garden’s Science Media Manager.


Common Lichens of Northeastern North America from NYBG PressLichens, those often colorful and sometimes exotic-looking organisms found growing on rocks, soil, and the bark of trees, have not gotten the respect they deserve, but a new book from The New York Botanical Garden Press may help change that.

Designed to be a user-friendly reference for non-specialists, Common Lichens of Northeastern North America is a light and easy-to-use field guide that covers the rich lichen flora of northeastern North America. Amateur naturalists, nature interpreters, forestry workers, land surveyors, researchers, and anyone who is interested in learning more about lichens will benefit from this book.

What are lichens, and why are they important?

Straddling the boundary between plants and fungi, lichens are composite organisms formed by the combination of a fungus and a plant-like component—usually an alga or a type of bacteria that contains chlorophyll. They are important to the full functioning of an ecosystem, and their presence or absence is an indicator of the health of that ecosystem.

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Open Sesame: An Intern Works to Reveal the Mystery behind a Common Food Plant

Posted in Interesting Plant Stories on April 10, 2015 by Genelle Diaz

Genelle Diaz-Silveira is a master’s student in biology at New York University who is completing her thesis at The New York Botanical Garden.


Harpagophytum procumbens Devil's Claw
Harpagophytum procumbens (a.k.a. Devil’s Claw)

In a world saturated with technology, it’s hard to remember the importance of plants to our daily lives. We depend on them for oxygen, food, medicine, clean air, and aesthetic pleasures, yet we devote less mental energy to them than we do to our smartphones and social media accounts.

Luckily, scientists at The New York Botanical Garden do spend some time thinking about plants. By documenting how plants function, how they are related to one another, and what they require from their environment, we aim to learn more about how life evolved on Earth and how we can continue to sustain it.

As a student researcher at the Botanical Garden, I’m doing my part by constructing a phylogeny—an evolutionary family tree—of the plant family Pedaliaceae. Commonly known as the sesame family, Pedaliaceae is rich in species that are both economically and medicinally useful. Examples include Sesamum orientale, which is cultivated for sesame oil, and Harpagophytum procumbens, which is used to treat joint pain caused by arthritis.

Harpagophytum procumbens Devil's Claw
Harpagophytum procumbens gets its colloquial name from the plant’s hooked fruit.

It’s the latter species—colloquially called “Devil’s Claw” due to its hooked fruit—that has inspired scientists here to resolve the muddied Pedaliaceae family tree. If we can paint a clear picture of how the family relates to its members as well as to those families closest to it, we may be able to forge a path to future drug discovery.

To elucidate the evolutionary history of Pedaliaceae, I’m primarily using molecular techniques. I’ve extracted DNA from multiple species—at least one representative of each genus—and begun to sequence different genes for each plant sample. The sequences will reveal genetic similarities and differences among my specimens. By analyzing the DNA data, I can come up with a good idea of how Pedaliaceae fits into the mosaic of plant life.

On its face, this may seem like a fairly straightforward endeavor. I obtain samples, extract DNA, sequence the DNA, and make a tree with the data. In actuality, the project has been full of mystery. That is to say, there are only a few contemporary scientists who have devoted time to Pedaliaceae, and herbarium specimens can be hard to come by in the US. These extra difficulties have made the journey extremely exciting.

Evolution can be messy; genetic distinctions among plant species are not always made clear by their physical characteristics. Unresolved families like Pedaliaceae often tentatively include orphan species that don’t clearly fit into one group or another. As this will be one of the first molecular studies of Pedaliaceae, I hope my results will provide enough evidence to definitively place those species. For the time being, I’m just happy to add to the naturalists’ tradition of cataloguing life.

Taking Conservation to a New Level: A Talk with the Garden’s Vice President for Conservation Strategy

Posted in Personalities in Science on April 8, 2015 by Stevenson Swanson

Stevenson Swanson is the Garden’s Science Media Manager.


Brian Boom New York Botanical Garden ConservationThe New York Botanical Garden recently established a new Conservation Program to increase its effectiveness as a global leader in conservation. Heading up this new initiative is Brian M. Boom, Ph.D., Bassett Maguire Curator of Botany and Director of the NYBG Press and Science Outreach.

Dr. Boom, who now has the additional title of Vice President for Conservation Strategy, has been at the Garden for nearly three decades. A specialist in the Rubiaceae (the coffee family), he was previously the Director of the Botanical Garden’s Caribbean Biodiversity Program, with overall responsibility for the creation, operation, and management of the institution’s botanical research and conservation initiatives in the Caribbean.

I sat down with Dr. Boom in his office on the fourth floor of the Garden’s Library Building to ask him about the new Conservation Program’s goals and initiatives.

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Take Note, Easter Bunny: Witches’ Broom Disease Sweeping World’s Chocolate Supply

Posted in Interesting Plant Stories on April 3, 2015 by Elizabeth Kiernan

Elizabeth Kiernan is a project coordinator for the William and Lynda Steere Herbarium at The New York Botanical Garden. She is currently working on a program to document the biodiversity of the Amazonian region of South America.


[Editor’s note: Easter is the second-biggest holiday for candy sales in the U.S., according to the National Confectioners’ Association, with sales of $2.1 billion in 2012. Each year, candy companies produce 90 million chocolate Easter bunnies.]

Moniliophthora perniciosa mushrooms on a cacao pod. (Photo: Google Images)
Moniliophthora perniciosa mushrooms on a cacao pod. (Photo: Google Images)

Chocolate lovers beware! Witches’ broom disease is your worst enemy. This fungal disease attacks Theobroma cacao, the tree from which chocolate is derived, and it has so altered chocolate production that in a generation no one may remember what chocolate as we knew it once tasted like.

T. cacao grows in the tropical rainforests of South America and West Africa. Here at The New York Botanical Garden, several cacao trees can be found in the Lowland Rain Forest Galleries of the Enid A. Haupt Conservatory, and there are preserved, dried specimens in the William and Lynda Steere Herbarium.

Humans unknowingly set the stage for the spread of Moniliophthora perniciosa, the aggressive fungus responsible for witches’ broom disease. To maximize the supply of cacao beans, which are used to make cocoa powder and chocolate, large monocultures of cacao trees were planted in South and Central America in the early 1900s from a selected handful of seeds, chosen for their delectability. This unintentionally placed the trees in a fragile position, since genetically similar populations are more at risk of succumbing to devastating pathogens. The fungus first appeared in Ecuador in the 1920s and has since spread throughout the Neotropics. Ten years after first being spotted in Bahia, Brazil, nearly 75 percent of the native cacao trees have been eradicated.

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