Like a mother checking on her newborn, Debbie Ackley had been waking at night to sneak a peek — online — at a plant-lover’s dream: a flower more than 5 feet tall that has its roots in Denver Botanic Gardens and is said to have an aroma of rotting flesh.

On Wednesday, Ackley was among the thousands of visitors who took the time to stop and smell the flower. They patiently waited as long as five hours to get a whiff of the 15-year-old corpse flower’s inaugural bloom.

Although no one seemed to mind the wait, several complained that the flower, endearingly named Stinky by gardens staffers, wasn’t as smelly as expected.

“I was hoping it would smell like rotten fish,” said Joni Klieger, 61. “It wasn’t as horrible as I thought it would be.”

Zuza Gaboush, 10, came with a surgical mask over her nose. She removed it once she realized Stinky didn’t live up to the name.

“I didn’t really smell anything, but it’s still really cool to see,” said Zuza, of Colorado Springs.

Ackley, also of Colorado Springs, is a member of the gardens’ illustration program. She had spent the past four days sketching the flower, watching it via live feed and eagerly awaiting bloom’s day.

“I feel like I have an intimate relationship with it,” she said, sketching the plant after three hours in line.

She likened the event to having a baby. “It’s like we’ve been in labor for three days,” she said. “I’ve been waking up at night and watching the live feed wondering if it’s grown. I’m not even a flower geek. I just feel invested.”

The rare flower has been an inconspicuous addition to the gardens’ Orangery greenhouse since 2007 when a Colorado man donated the plant, which had outgrown his greenhouse.

A few weeks back, staffers started to notice the flower changing.

“It just looked different,” said Nick Snakenberg, curator of tropical collections.

To the delight of the gardens’ horticulturists, the flower started growing — it’s now about 5 feet, 3 inches tall — and late Tuesday, it graced the greenhouse with its bloom and an odor.

The corpse flower, scientifically known as Amorphophallus titanum, takes from eight to 20 years for its first bloom, Snakenberg said. Subsequent blooms, which last for only two days, come every seven to 10 years. The plant spends much of its life in a vegetative state, gathering energy to produce its smelly flower.

That’s why the plant is such a spectacle.

“It could be a once-in-a-lifetime experience,” Snakenberg said.

Another draw? The stench.

The flower is said to emit a scent comparable to rotting flesh — all the better to attract carrion insects that choose to lay eggs inside dead and rotting animals. These insects then pollinate the flower, Snakenberg said.

Once word got out that the first corpse flower bloom in the Rocky Mountain region was imminent, folks couldn’t wait to get a whiff and a photo.

At 8:30 p.m. the line outside the gardens, along York Street, to get inside the grounds, still stretched from the East 10th Avenue entrance just about all the way to East 9th Avenue, more than 200 people deep.

Once inside, the line to view the corpse flower snaked back and forth several times under a huge rectangular tent and the wait remained about four hours.

Most people in the lines were patient and friendly. One man said aloud: “This is the longest line ever at the botanic gardens!”

Nancy Bedell, of Boulder, drove to Denver after work to view the attraction. She’s been watching the flower for the past week on the Internet.

“I’m ready to see it,” Bedell said excitedly. “I can’t miss it!”

Anne Elliott, of Westminster, with her daughters, Sadie, 8, and Olivia 10, smiled as they exited the greenhouse after an up-close look.

“Even if there is another (future) bloom, I am not waiting in another line,” Elliott said with a laugh.

Sonja Nazareth, who viewed the flower along with Elliott, described the long wait as “silly,” but also acknowledged that the experience is a “once in a lifetime event.”

When asked about the flower’s aroma, Sadie just wrinkled her nose.

Olivia blurted out: “It smells like garbage, raw fish!”

Hart Axley, 84, said he expected the flower to be a bit taller, and a bit stinkier.

“I didn’t get close enough to be knocked over by the odor,” Axley said.

Axley, who was raised on a farm in Wisconsin, admitted that he may have a high tolerance against foul odor.

“I shoveled plenty of manure in my day,” he recalled.

Gardens spokeswoman Erin Bird explained that not all corpse flowers are alike, conceding that the Denver plant isn’t overly offensive.

“It’s actually not quite as stinky as we anticipated,” she said. “You’ll get kind of a random whiff, and it will hit you.”

But smelly or not, Stinky still attracted crowds.

Within about five hours, the gardens saw at least 5,000 visitors, Bird said. She thought at least 10,000 people would make it in by the special pushed-back closing time of midnight.

“If somebody arrives at 11:55 p.m., we’ll let them in,” Bird said. “If needed, we’ll stay open past midnight.”

On a typical day, Bird said the gardens see about 2,000 visitors.

Members got early Stinky admission Wednesday: 6 a.m.

Bird said the facility, which as of Wednesday had about 46,000 members, has seen an increase in memberships, indicating that folks were willing to pay extra for a big breath of rotting flesh first thing in the morning.

The parking lot across from the gardens was almost permanently full Wednesday, Bird said, and parked cars lined the surrounding neighborhood for blocks.

The Stinky hoopla is an even rarer occurrence, Snakenberg said, because of the dwindling numbers of such flowers in the wild.

Currently listed as “vulnerable,” Snakenberg said the plant soon could be endangered if deforestation continues.

“This is a big deal,” said Kristin Lott of Parker. “There’s been a lot of hype, but it’s worth it. How often will I get to see this?”

Staff writer Kieran Nicholson contributed to this report.

Why so smelly?

The corpse flower stench stems from a deceitful attempt to get pollinated. The flower emits an odor similar to rotting flesh to attract carrion insects that lay their eggs inside dead, rotting animals. The insects that fall for the flower’s trick then go on to pollinate the bloom.

Want a whiff?

The gardens will be open 6 a.m. to midnight Thursday and 9 a.m. to 9 p.m. Friday. Photographs are permitted.