It has taken seven years to grow, has an odour that has been compared to decomposing flesh and blooms for no more than three days before collapsing.
But it was all worth it when a titan arum (more commonly known as corpse flower) bloomed at the Melbourne Botanic Gardens on Tuesday afternoon.
Melbourne Gardens director Chris Cole said: "It's great for the public to have this opportunity to see just how amazing this plant is and gain an appreciation of nature and the work being done by botanic gardens around the world in conserving plants that are at risk in the wild.”
Garden visitors have flocked to the tropical hothouse all week in anticipation of the flower's bloom.
A queue of Christmas Day visitors waited outside, with one enthusiast saying it was "exciting to finally see one in the flesh".
The corpse flower is the largest unbranched inflorescence in the world. It can grow up to three metres high and is native to western Sumatra, where it grows in rainforests.
It flowers infrequently in the wild and more so when it is cultivated. The flower started to bloom about 3pm and will have peaked during the night.
Before flowering, A.titanum, which means "misshapen giant phallus", consists of a fragrant spadix (a hollow, flower-bearing central spike that looks like a French breadstick) of flowers wrapped in a collar-like structure called a spathe, which resembles a large petal to attract pollinating insects.
Inside the spathe's sheath the spadix bears two rings of small male and female flowers. The female flowers open first, followed by the males a day or two later to stop the plant from self pollinating.
Commenting on the first-time event for Melbourne, Mr Cole said: “It's very exciting. As the titan arum opens, hundreds of little male and female flowers inside emerge in a colour resembling rotten flesh, then the spadix heats up and the stench is released as a sign to flies and beetles that the plant wants to be pollinated.
"The inflorescence can grow up to three metres but the bloom only lasts for two or three days, then it withers and collapses.”
Titan arum has enthralled botanists, gardeners and plant enthusiasts since its discovery in 1878, deep in a Sumatran rainforest, by Italian botanist Odoardo Beccari.
The stinking bloom is classified as vulnerable now that deforestation in Indonesia has destroyed much of its native habitat.
Mr Cole said that judging by past flowerings at other venues such as Sydney's Royal Botanic Gardens, he expected up to 10,000 visitors over the next couple of days to see the plant and take in the pungent smell.
No doubt there will also be a bit of nudging and giggling at its suggestive shape. “Sex sells,” Mr Cole said.
The glasshouse is open daily from 10am to 4pm and until 6pm on the three days of flowering.