Category Archives: Plant

The Smell Of A Corpse Flower? Meh

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Even up close, the titan arum doesn’t look real. But I didn’t wait in a long line outside the U.S. Botanic Garden just to see the plant. I wanted to smell it — would the “corpse flower” live up to its name?

No.

Not that I’ve ever smelled a corpse and could compare that. But I’ve encountered enough other awful scents (trash rotting in a heat wave, burned brakes on a Metro train, a New York City sidewalk) to know that this one was not too bad. A fellow visitor said that the scent reminded him of fish rotting on the seashore. I got a whiff of really bad body odor (which could have been just really bad b.o. — everyone is pretty gross and smelly this time of year in D.C.). It was much less than I was expecting, and less than others expected as well. Perhaps the plant had already dispensed the nastiest of its smells before I got there.

The titan arum employs its rotten scent as a lure for insect pollinators. Researchers have determined that a chemical called dimethyl trisulfide is responsible for the smell. Dimethyl trisulfide is also produced during the cooking of onions and leeks, as well as in the early decomposition of a human body; so corpse flower is actually an accurate term.

For me, though, it was the flower’s size — eight feet tall — that was really amazing. The plant looked more like a prop for a sci-fi movie than something you’d find here on earth. But the flower can be found growing in the wild, in the forests of Sumatra in Indonesia. And I suppose that, compared to the tame vegetation around Washington, Sumatra would appear to be other-worldly.

One weird thing I discovered today, though, is that titan arum isn’t the plant’s real name. It’s scientific name is Amorphophallus titanum. (The genus name means “misshapen phallus.”) The name titan arum was made up by famed BBC presenter David Attenborough — he didn’t think that saying Amorphophallus made for appropriate television and came up with the alternative. The name stuck.

Image by the author

July 23, 2013Permalink Leave a comment

Bad News For Animals That Live In The Subnivium

voleYou’ve probably never heard of the “subnivium.” That’s because it’s a term that scientists just made up (they do that). The group of ecologists and biologists, led by Jonathan Pauli of the University of Wisconsin, say in an article recently published in Frontiers in Ecology and the Environment that the subnivium is the seasonal refuge that occurs below the snow where there’s environmental stability. It’s cold there, with temperatures near freezing, but this region serves as a retreat from the harsh, sometimes changeable environmental conditions above.

A healthy subnivium contributes to a healthy ecosystem. Insulated soil lets microbes and fungi breathe and proliferate and process organic matter. Plants benefit from increased carbon dioxide and warmer temperatures, especially during late winter and early spring. Many animals — a list that includes invertebrates, amphibians, reptiles, birds, and small mammals — will use the region to hide out during the winter, feeding off each other or any vegetation they can find. There are whole ecosystems below the snow.

But warming conditions have led to many changes in the patterns of snow in the Northern Hemisphere (that’s where most of the world’s snow is found): The month of maximum snow cover has shifted from February to January. The spring melt is about two weeks earlier than it was decades ago. The extent of land covered in snow in the winter has been shrinking. In many places, the amount of time when snow is more likely than rain has decreased by more than one and a half months. Snow depths are decreasing, as are snow packs. The list goes on and on.

“Snow cover is becoming shorter, thinner and less predictable,” Pauli said in a statement. “We’re seeing a trend. The subnivium is in retreat.”

With all these changes, the stability that the subnivium provides is therefore disappearing. What does that mean for the ecosystems that thrive there? One worry is that organisms, such as plants, that are exposed to cycles of freezing and thawing could experience tissue damage. Others, like voles or insects, that lose the layer of snow that hides them may be subject to predation by birds or other critters.

“Decay of the subnivium will affect species differently, but be especially consequential for those that lack the plasticity to cope with the loss of the subnivium or that possess insufficient dispersal power to track the retreating range boundary of the subnivium,” the researchers write. Those that can adapt to the loss of stability or can move to places where there’s still reliable snow cover will do better than others. Adapt or move — those seems to be the only two options for surviving climate change.

Image of vole courtesy of flickr user musubk

May 7, 2013Permalink 2 Comments

There’s A Lot Of DNA In Tulips

IMG_6219One of my favorite spring spots in Washington, DC, is the Tulip Library. The cherry blossoms get all the attention, but this collection of nearly 100 varieties of tulip (such as the one above) that bloom from April to early May is truly special. These tulips aren’t wild, but that doesn’t mean we can’t learn something today about their wild brethren.

A few years ago, a plant scientist at Leiden University in the Netherlands, Ben J. M. Zonneveld, published a study of the tulip genus genome in Plant Systematics and Evolution. He had collected more than 400 wild tulips from Europe and Asia and concluded that there are at least 87 wild species of the flower (he has since found number 88). He couldn’t determine exactly where the ancestor of the modern tulip came from, but he was certain that it wasn’t Turkey, despite legends that say that’s where the flower originated.

Zonneveld also discovered something odd about tulip DNA — there was a lot of it, and different tulip species had different amounts, ranging from 32 to 69 picograms (a millionth of a millionth of a gram) of DNA in every nucleus. DNA in the human nucleus, in comparison, weighs only 7 picograms. No one has figured out yet why the flowers have so much more DNA than we do, but the tulip genome has about the same number of genes as found in the human genome, so it’s not that they’re overwhelmed with genes.

It’s kind of fitting that the tulip research comes from the Netherlands, as the Dutch have been tulip mad for centuries. Zonneveld is continuing that tradition; he says he has 2,000 different types of tulips in his personal collection, including many varieties that he created and that exist nowhere else. It kind of puts the Tulip Library to shame, but at least that garden is a lot closer to home.

Image of the Tulip Library taken by the author

April 16, 2013Permalink 1 Comment