Stink coming in California

Parent and offspring set to entertain

It has been quite a year for the spectacular Amorphophallus titanum, often dubbed the smelliest flower in the world.

In May, three specimens held at the Royal Botanic Gardens, Kew, London, UK, burst into flower.

It is rare for one plant to bloom twice in cultivation

Brendan Craughwell, conservation assistant

Huge crowds were drawn to witness their enormous bulk and experience their "fragrance" - described by many as a cross between excrement and rotting flesh.

Last month, a plant at the University of Wisconsin-Madison in the US flowered. And now, a specimen at The Huntington Botanical Gardens in San Marino, California, looks set to blossom - for the second time in three years.

It is extremely rare to see this species flower at all. Since the first blooming event under cultivation was recorded at Kew in 1889, an Amorphophallus titanum has been seen to go into flower fewer than 10 times in the UK and not many more in the US.

Rotting apples

The plant, also known as Titan Arum or the "corpse flower", is found naturally only in Sumatra. It is not naturally self-pollinating, which makes cultivation of single plants in botanical gardens difficult to achieve.

	Enlarge image
The Amorphophallus titanum at Kew Gardens in London.

The spadix, or central column, can reach over two metres tall. A. titanum is described by botanists as an "inflorescence", meaning it is actually a cluster of flowers.

These are found hidden inside the base of the spadix. When the spathe - the large frilly edged leafy structure surrounding the spadix - opens, the flowers are mature and give forth their famous stink.

In the rainforests of Sumatra, this would attract pollinators such as carrion beetles and sweat bees.

At The Huntington, botanists have to accelerate the maturation of the pollen before the flowering event - the reverse of what happens in the wild. The botanists take the male parts, the anthers, from the plant and put them in a bag with rotting apples.

This readies the pollen so it can be "painted" on to the plant's female parts.

Stressful time

When The Huntington staff did this three years ago, they got their A. titanum to bear fruit and seeds.

"It is very exciting for us to have the same plant bloom, because we are able to display it next to one of its offspring from the bloom three years ago," Brendan Craughwell, a conservation assistant at the Huntington told BBC News Online.

Looking down the spadix of the University of Wisconsin-Madison plant

"It is rare for one plant to bloom twice in cultivation. The offspring is one of six to be produced from the first known successful self-pollination of an A. titanum.

"The bloom this time is a few inches shorter than the last. We suppose that this is due to the stress of the earlier bloom."

The Huntington A. titanum began to open on Monday. The botanical gardens, normally closed on a Monday, stayed open to allow visitors to view the plant.

Flowering, when it comes, lasts only two to three days.

Main image courtesy of The Huntington Library, Art Collections and Botanical Gardens.