Sex and deception: why the corpse flower smells like death

Its scientific name means giant misshapen phallus, and indeed the corpse flower's notorious stench is all about sex — and trickery.

A corpse flower is currently in bloom at Vancouver's Bloedel Conservatory, drawing lines hours long for a whiff of a plant that smells like rotten flesh, with notes of old fish and "decayed cabbage."

But its devious strategy isn't there to attract tourists or botanists.

The smell, nocturnal bloom and generation of heat — near human body temperature — are all enticements for nighttime pollinators, an elaborate hoax to procreate across great distances in the Sumatran forests where it evolved.

What is that smell?

The Amorphophallus titanum, also known as titan arum or corpse flower, was first described in Western science by an Italian naturalist in 1878, who shipped seeds from Indonesia to England where eager botanists began cultivating the giant plant.

It first bloomed in June of 1889, a wonder noted by The New York Times, which likened the smell to a London fishmarket at noon on a summer's day.

"It emits ... the very foulest odour known to the upper world, and the strongest."

Since then, the species has continued to fascinate, drawing crowds and appearing in pop culture from 1993's Dennis the Menace to the Simpsons.

And science has been hard at work pinning down the exact ingredients in the smell, identifying more than two-dozen volatile compounds, including sulpherous compounds often associated with rotten eggs.

Using an "electronic nose," researchers at the University of Tokyo even published what they call an objective description of the smell, which begins as "decayed cabbage, garlic and pungent sour," before hitting fish and urine near the end.

Smelling like death has its perks

Even in the 1880s, "so far has Darwinism spread among the masses," the Times noted, crowds who came to smell the corpse flower wanted an evolutionary explanation.

Indeed, smelling like death can be useful, says Ernesto Sandoval, the manager and curator of the UC Davis Botanical Conservatory, which has four adult corpse flowers in its gardens.

It attracts carrion flies, dung beetles and other pollinators that are looking for rotting meat — a good move for a rare plant spread over long distances.

"Since individuals of this species are pretty far apart from each other, flies make really good pollinators, along with beetles, because they're going out pretty long distances looking for dead things to eat."

Insects 'totally duped'

The total display may only last 48 hours, and it can be years between blooms for any one corpse flower, so the plant goes all out for its brief chance at sex.

It's a fascinating display of mimicry, because the plant not only smells like rotten flesh but tries to feel like it too.

During the first, most pungent night of flowering — known as the female flowering phase — the plant heats itself up to between 36-38 C, to emulate the heat generated by a decomposing carcass.

As a result, insects are tricked into pollination.

"The flies and the beetles don't get anything out of visiting the flowers," said Sandoval, unlike, say bees gathering pollen and nectar for honey.

"They're totally duped into being so convinced it's a dead animal that sometimes they even lay their ... eggs inside the flower."

'Beauty and stink'

For Sandoval, whose facility has hosted the spectacle of eight corpse flower blooms since 2003, titan arum has become a useful ambassador for the plant world.

"People ... get pulled in by the strange fascination of beauty and stink," he said.

"That's what I think is beautiful about this species. It ... draws people in that normally wouldn't think about going somewhere to look at a plant."