A GIANT flower with the scent of rotting flesh is soon to bloom in the Mount Lofty Botanic Garden.

BBC naturalist Sir David Attenborough was the first to observe “tiny sweat bees” pollinating the world’s biggest flower, during filming of The Private Life of Plants. They are attracted to the scent, which Sir David described as smelling “very strongly of dead fish”.

“It only flowers once in a thousand days and when the flower develops it only lasts for three days, so very few people have seen it,” he said.

Plant propagation curator Matt Coulter believes the rare botanical event is a first for South Australia.

He’s “pretty definite” on that fact, or at least 95 per cent sure, having checked with members of the flower’s fan club at the International Aroid Society.

It’s certainly a first for our Botanic Gardens. But it won’t be the last.

“We’ve worked out how to propagate them vegetatively (from leaf cuttings rather than seed), so we’ve got more than a hundred plants now,” Mr Coulter said.

“That’s ground-breaking work. Very few people in the world have ever done that. Hopefully in the future we have enough that we can get a flower every year.”

Commonly known as the corpse flower, the titan arum (Amorphophallus titanum) from the rainforests of Sumatra is an endangered species.

That means it’s against the law for the Botanic Gardens to sell the plant or seed.

Mr Coulter predicts the plant will flower in the next four to eight days and then it will be open for only 24 to 36 hours.

“We will only know the day before that it’s going to flower,” he said.

“The spadix (giant yellow phallic spike) stops growing, so it stops growing vertically and then you start to see some colouration on the spathe (burgundy upturned skirt).

“So at the moment it’s green but once it starts going a purply sort of colour you know it’s going to open the next day or two.”

The Mount Lofty Botanic Garden will open the nursery to the public for the event, although the garden shuts when the fire danger rating is severe or above.