“She’s a delicate lady”

Biologists are hoping that Rotty Top, UT’s only mature Corpse Flower, soon blooms. Photo by J.J. Stambaugh

Rotty Top is turning out to be fairly shy, for a plant. 

The specimen of Titan Arum, better known as a Corpse Flower, has becomes one of Big Orange Country’s most celebrated denizens in recent days as crowds of well-wishers have crowded through the Hesler Biology Building on the University of Tennessee campus to get a glimpse of the botanical wonder.

They’re hoping, believe it or not, to eventually catch a whiff of an infamously odiferous display, for when the Corpse Flower blooms it releases chemicals that mimic the scent of decaying flesh.

But Rotty Top (so named because, well, why not?) isn’t blooming as expected.

While this belle of the botanical ball’s keepers said Wednesday they aren’t worried — yet, anyway — they’re keeping a close eye on the Titan Arum to ensure that everything is okay. 

“She’s a delicate lady that apparently is not ready to bloom quite yet. We are hoping it will happen in the next couple of days,” said Jeff Martin, greenhouse manager for UT’s Department of Ecology and Evolutionary Biology.

“The smell is getting stronger,” Martin said. “You can never tell once one starts the process if it will be able to finish it. Sometimes they can’t bloom. Obviously, you don’t hear about those as often, but it’s happened.”

If Rotty Top is unable to bloom then its tall, leafy structure will likely die back, leaving behind the Titan Arum’s corm. The corn is the lumpy, potato-like base of the floral structure, and Martin said it should eventually send up another stalk although another decade may elapse before it can try to bloom again.

In 1878, Italian botanist Odoardo Beccari discovered the Titan Arum on the tropical island of Sumatra in the Pacific Ocean and sent seeds and samples back home. They were shared among several gardens, with the first one successfully cultivated in 1889 at the Royal Botanic Gardens at Kew, England.

“Since then, they’ve been kind of passed around different botanical gardens and collections like ours,” Martin said.

“Rotty Top” was acquired from the University of Connecticut in 1999 and has only now grown large enough to bloom, he explained. There are several other examples of Titan Arum in the UT greenhouses in various stages of growth.

A Corpse Flower corm. Source: UT

Tragically, the Corpse Flower is considered an endangered species, with only an estimated 1,000 of them surviving in the wild. That’s a decline of around 50 percent in the last century-and-a-half, with most of the losses attributed to logging and the conversion of tropical rainforest to oil palm plantations, Martin explained.

“There seem to be more in private gardens and collections as specimens than there are in the wild,” Martin continued. “A lot of people may have one, but they will never get it to the flowering stage unless they give it the right conditions.”

Successfully reproducing the hot, humid conditions of its tropical home is one of the biggest challenges that comes with caring for a Corpse Flower, which isn’t even a “flower” in the usual sense, explained Assistant Greenhouse Manager Kaitlin Palla.

“Even though it looks like one flower, it’s actually a lot of male and female flowers at the base of this tall structure,” Palla said. “It’s actually the world’s largest unbranched inflorescence. It’s a flowering structure, like a sunflower or lavender — those are different types of inflorescences.”

In her lectures, Palla uses Titan Arum as an example of how plants develop adaptations to differing environments.

“Its stem is modified into something we call a corm, which is a potato-looking structure that stores a lot of water and nutrients for the plants,” she continued. “That corm has to get big enough, storing a lot of nutrients, to support the growth of a flower. That’s why it takes almost a decade for the initial bloom to occur, because that flower is such an energy suck.”

Martin and Palla described the odor as a combination of “Limburger cheese, garlic, rotting fish, and smelly feet.”

Rotty Top began showing unmistakable signs that it was preparing to bloom on July 14, and botanists estimated that it would take about one to two weeks for the full bloom to occur. 

“The female flowers on the lower half of the stalk bloom first, followed roughly 12 hours later by the male flowers on the upper half of the stalk. This careful timing prevents self-pollination, ensuring genetic diversity,” according to a description of the process provided by Martin and Palla.

A paintbrush will be used to dab “donor pollen” from another individual onto the receptive stigmas of female flowers. If they are successfully fertilized, they will produce fruit for the next nine months. Once the fruit ripens, the towering stalk will die back, leaving behind the now-dormant corm to rest until it begins to grow leaves again (typically a year or so later). 

Jeff Martin and Kaitlin Palla, who manage the greenhouses belonging to UT’s Department of Ecology and Evolutionary Biology. Photo by J.J. Stambaugh

Once the Corpse Flower opens up, the stench is expected to be at its most potent for the first 12 hours or so, when the female flowers are ready to be pollinated. The smell will start to dissipate as the male flowers open up, covering insects that have gathered during the night with pollen. 

“The flowering process lasts about 24 to 36 hours and, once we notice it opening, we’ll do a public announcement,” said Martin.

Officials plan to keep the front doors to Hesler open to the public until midnight on the day that Rotty Top finally blooms and then stay open from 7 a.m. to 7 p.m. the following day.

“We’re waiting for that last protective leaf to dry up,” Palla said. “Once that skirt-like structure starts to loosen away from the column, then we know it’s about to happen. It takes its sweet time and then, all of a sudden….” 

UT’s indoor plant collection is housed in four greenhouses and contains 575 different types of plants. The collection is used by majors in biology, plant science, and ecology and environmental biology, and it’s visited officially each year by 300 students in 10 different classes, according to UT.

Those interested in supporting the Biology Greenhouse can make donations to the Dr. Ken McFarland Greenhouse Support Fund on UTK’s Giving website (http://giveto.utk.edu).

J.J. Stambaugh can be reached at jjstambaugh@hardknoxwire.com 

Published on July 29, 2021