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For days, Coloradans have held their breath — and their noses — as they watched the plant that has suddenly become Denver’s most famous flower.

The 15-year-old titan arum, better known as Stinky the corpse flower, has long sat serenely in a Denver Botanic Gardens greenhouse, looking like nothing more interesting than a large, stocky green stem.

But recently it’s undergone a rapid transformation, shooting up four feet in the course of just a few weeks. And late Tuesday night, Stinky unfurled its ruffled green-and-purple leaf and began to bloom.

The effect was disgusting.

Like “a number of dead mice maybe rotting in an abandoned gym locker,” curator Nick Snakenberg told Denver TV station CBS4.

Over the course of the next 48 hours or so, Stinky will release the unbearable scent of a decaying corpse as it tries to attract the bugs that will pollinate it. Then the flower will die, and the plant will go dormant for another half dozen years until it’s ready to bloom again.

But not before the Denver Botanic Gardens have squeezed every ounce of publicity out of its bizarre new blossom.

According to USA Today, the gardens have seen a record 30,000 visitors in the past 10 days — almost as many as it gets in some months. The plant got its own hashtag — #StinkyDBG — on which it bantered with other corpse flowers around the country. The garden gift shop began selling limited edition corpse flower t-shirts, and a local doughnut shop started churning out corpse flower doughnuts. A local TV station even has a live camera trained on the blooming plant.

The gardens will be open until midnight for the two days that the flower is in bloom.

“This is super unique to have just one plant that people are coming to see,” Denver Botanic Gardens spokesperson Erin Bird told USA Today. “I think it’s just human curiosity, the interest in the weird and the absurd, and also the anticipation of the unknown that is stringing us along. We don’t know when Stinky will bloom.”

Though DBG staff have known that a bloom was in the works for weeks, they didn’t know exactly when the corpse flower would unleash its characteristic putrid odor.

The source of the stink is the “female” flower at the base of the plant’s spadix, the tall structure at its center. During the initial part of the bloom, the female flowers emit a nauseating mixture of chemicals: dimethyl trisulfide (which smells like rotting onions), trimethylamine (the essence of rotting fish) and isolvaleric acid (the smell of old sweat socks), among others. The plant also generates heat, giving it the approximate temperature of a human body.

People typically find the combination repulsive (though it doesn’t seem to stop us from flocking to see the flowering plants) but the stench and the warmth attract hordes of flies and carrion beetles. The insects — who are hopefully carrying pollen from other flowers — then get trapped inside the plant.

When the “male” flowers open roughly a day later, they capture the pollen from the captives and sprinkle their own pollen onto them, before releasing the bugs back into the world to pollinate other plants. The elaborate two-day process prevents the plants from self-pollinating.

Stinky is one of at least three corpse flowers to bloom in the U.S. this year — one of the plants stunk up the botanic garden at University of California – Berkeley earlier this year, and another is set to bloom at the Chicago Botanic Garden within a couple of days. And a more than five-foot specimen graced the U.S. Botanic Garden in Washington with its putrid scent in July 2013.

But the phenomenon is extremely rare, both for cultivated plants and for those growing wild in the rainforests of Sumatra, Indonesia. When a bloom was documented for the first time — at the Kew Royal Botanic Gardens in the U.K. in 1889 — the police had to be called in to control the crowds, according to public radio station KPCC.

The corpse flower brought its sweaty sock stench to the U.S. in 1937, when it bloomed at the New York Botanical Garden in the Bronx. After that famous bloom, the borough made the plant its official flower. But the symbol was dropped in favor of the more appealing day lily in 2000.

”I hate to think of the corpse flower as the Bronx flower, because people would think the Bronx and think, ‘The Bronx stinks,”’ Michael Ruggiero, the senior curator for horticulture at the New York Botanical Garden, told the New York Times. ”The Bronx is a people place, and the corpse flower is not a people plant.”

The corpse flower gets its official name — titan arum — from none other than Sir David Attenborough, the famous BBC presenter. In 1994, he traveled to Sumatra with a crew to film a wild blooming for his series “The Private Life of Plants.” But he worried that the plant’s Latin name, Amorphophallus titanum, might offend refined British sensibilities (“amorphopallus” means what it sounds like).

“I didn’t think you could constantly refer to it like that on a popular show, so I invented a popular name – the Titan Arum,” he told the Telegraph in 2008. “And everybody now calls it the Titan Arum, it’s in all the books.”

Like the thousands of people who have flocked to see the Denver plant in bloom, Attenborough was captivated by the noxious plant. And although it’s certainly an impressive species — one of the largest flowering plants in the world — really, humans are in it for the stench. In 1996, when a corpse flower at Kew wasn’t quite as smelly as anticipated, visitors told the New York Times they were sorely disappointed.

“I brought scarves to cover my nose and everything,” lamented one woman, “and I can’t smell a thing.”

To Paul Licht, the director of the UC-Berkeley Botanical Garden, it’s no surprise that humans find themselves drawn to the corpse plant just as much as the bugs.

“It’s a fascinating flower, and it stinks,” he told KQED when the California plant bloomed in July. “But in a way that somehow appeals to people. People go to horror movies to be scared, right? Well, they go to see this flower to be made nauseous.”