Anticipation of the soon-to-bloom stinky "corpse flower" drew record crowds to the Cockrell Butterfly Center this weekend.

Visitors saw, but didn't yet smell, the endangered species, which is expected to bloom by Wednesday.

The museum is recording the flower's progress with a live webcam. And roughly 3,000 people turned out Sunday — five to seven times the center's average crowd - to catch a glimpse, said Latha Thomas, the vice president of marketing and communications.

"We are staying open late to accommodate the crowds, and we may go 24 hours if we have to," Thomas said. "We want everyone to be able to see the flower who wants to."

The flower, native to the Sumatran rainforests in Indonesia, is one of the biggest and most mysterious flowers in the world. It's bloom is so rare that only 28 other bloomings have been observed in the United States.

It gets its name from one of its more unique traits: When the "corpse flower" opens, the smell of meat flies' meals permeates. Those flies - the plant's primary pollinators - feast on rotting flesh. "It smells really bad," said Zac Stayton, a horticulturist at the museum. "I'm told it's one of the worse smells you will come across."

Crowds that waited an average of 30 minutes to see the flower Sunday were spared the smell.

"Is this it? Where is the stinky plant?" said Carmelita Lapus, a visitor at the museum. "We were really hoping to see it open now, but if it doesn't we will be back tomorrow."

The odds that the plant will bloom today are about 80 percent, Stayton said. It should certainly open by Wednesday, he added.

The flower will most likely start blooming around 3 p.m. today and should take four hours to fully open.

The flower will stay in bloom only about two days, Stayton said.

"We don't know what triggers them to bloom," said Tom Rice, a docent with the museum. "It's one of the great mysteries of botany."

matthew.woolbright@chron.com