Experts at the Inverleith attraction have been watching the giant Amorphophallus titanum, or Titan Arum, in the glasshouses for weeks – and last night announced it was set to start flowering today.
But thanks to warmer weather, the plant at Paignton Zoo in Devon has pipped it at the post.
The two plants are roughly the same age – though nearly 500 miles apart – and had been set to flower at around the same time.
The exotic plant, which gives off a smell like rotting flesh, generally flowers every seven to ten years – but staff at the Botanics have been waiting on theirs for more than 12, and it has never before been seen in Scotland.
Today, Botanics staff said visitors would be able to “follow their noses” to track down the spectacle, as it signalled it was about to flower by emitting its pungent smell.
One of the largest flowers in the world, it is known as a carrion flower, or corpse flower, thanks to its odour.
Senior horticulturist Sadie Barber said: “We are thrilled to finally see, and smell, this incredible curiosity of the plant world after 12 years of careful cultivation.
“It really is one of the most extraordinary flowering plants we have ever seen, and great to think that something that grows naturally so far away can be enjoyed by visitors to the garden here in Edinburgh.”
The full bloom only lasts one or two days and with this being the first time a Titan Arum has flowered in Scotland, visitors are expected to flock to the Glasshouses over the coming days to see if the flower, nicknamed “New Reekie”, lives up to its smelly reputation.
A good-natured rivalry had grown between Edinburgh and Devon as the two plants vied with one another to be first, with Paignton Zoo tweeting: “It’s #ClashOfTheTitans! @TitanArumRBGE v @PaigntonZoo. Which one is going to get stinky/flower first?”
But the plant in Devon just won, as it blossomed last night with a bloom almost 10ft wide and 10ft tall.
Peter Wilkie, a tropical tree botanist working for the Botanics, said he wasn’t disappointed that its Titan Arum had failed to bloom first.
He said: “First doesn’t mean better and we are going for quality. This will allow the people of Scotland and northern England to see the wonder of plants and that’s the main thing.”
Dr Wilkie, who has been over to the plant’s native habitat in Sumatra, has never before seen a Titan Arum in flower.
He also revealed that the flower would ultimately be added to the Botanics’ Herbarium, which includes more than three million specimens.
First it will be specially dried, pressed and treated so it “lasts forever” and the horticulturists of the future will be able to study it.
The Titan Arum had grown more than an inch in 24 hours when it was measured at 1pm yesterday and now stands more than 8ft tall.
A spokeswoman from the Botanic Garden confirmed that, even before the Titan Arum had flowered, visitor numbers had more than doubled since last year.
Between June 13 and June 22 in 2014, the Botanics had 2651 visitors to the Glasshouses but for the same period this year there have been 5728.