“Most of the odors are going to be those sulfuric, garlicky, even fishy scents,” said Kaitlin Palla, assistant greenhouse manager for UT’s Department of Ecology and Evolutionary Biology. “Those are produced by two of the main compounds the central column will produce. It’s heating up to 98 degrees right now, so it’s really aerosolizing those compounds in particular. But there’s also floral notes from the skirt-like structure around the bottom.”

The titan arum evolved to use the scents to attract insects that feed on dead animals such as flesh flies and carrion beetles.

Although opinions in the crowd differed as to what exactly Rotty Top smelled like, everyone agreed the odor was singularly foul. 

“Hot garbage,” said Ricky Williams, who snapped pictures of the corpse flower while his wife, Rebecca, posed in front of the glass. “Hot, stinky garbage that’s been in the sun too long.” 

“Yes, that is certainly gross,” said Linda Moore, 30, who hurried to UT from Oak Ridge after learning from social media that Rotty Top had finally bloomed. “Was it worth driving down here and going into work late? I don’t know. Probably, since it’s certainly memorable.”

It was, of course, more than memorable for the UT horticulturalists who have cared for Rotty Top since the titan arum was a mere pup — or, in this case, a mere corm.

According to Palla, a corm looks like a swollen potato. The central column and flowers that eventually appear all grow out of the corm, which spends 10 years or more collecting water, nutrients and energy before it is ready to bloom. Mature columns can sometimes grow 10-feet tall, but Rotty Top is considerably more modest at 44 inches in height.

When a corpse flower blooms, all the stored energy is poured into opening the top, heating itself to 98 degrees, and producing the chemical compounds that make it such a smelly houseguest, Palla explained.

“I feel like I’m witnessing the birth of a child,” she said. “I feel like I’ve been midwife to it.”

Palla said one of the most rewarding elements of caring for Rotty Top has been the opportunity to study how the titan arum evolved into such a highly specialized life form. 

“It’s wonderful to see the wild permutations these things take,” she said. “The color can sometimes be a lot more bright red or deep purple. I think ours is perfect. It almost looks like velvet.”

To Jeff Martin, greenhouse manager, the blooming of Rotty Top came as a tremendous relief. 

He and his staff had been preparing for the event since their charge began showing the traditional signs of preparing to bloom two weeks ago. 

“There are some titan arum that don’t open and, as much attention as this one has received, we were very worried that people would be upset if it didn’t open,” Martin said. “Granted, plants are plants and they do it their way. When I got the call this morning it was just great stress relief.”

Martin said he’s been surprised but pleased by the large crowds that have come to see Rotty Top. 

“What I feel the most is excited from all the exposure that folks are getting of biology and the greenhouses,” he said. “I didn’t realize this many people would be interested, and it’s great. Hopefully, this will get people a little more interested in other types of plants.”

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.

Rotty Top was acquired from the University of Connecticut in 1999 and has only now grown large enough to bloom, Martin said. There are several other examples of the titan arum in the UT greenhouses in various stages of growth.

Despite the enthusiastic interest in the corpse flower, it’s an endangered species. Populations have declined by about 50 percent in the last 150 years, with most of the losses attributed to logging and the conversion of tropical forests to palm oil plantations, according to Martin.

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 donation site.

J.J. Stambaugh can be reached by mailing “jjstambaugh” at hardknoxwire.com