You don’t often find crowds of people flocking together to take in the pungent scent of rotting flesh, but that’s exactly what happens every time a corpse flower blooms at a public garden. In fact, thousands turned out to get close to the flower of the world’s stinkiest plant in January in Australia. It proved such a drawcard that Sydney’s Royal Botanic Gardens kept the gates open until late at night to accommodate the eager fans.
“Usually, you have to get close to a flower to be able to smell it,” said biologist Olivia Murrell. “That is not true for the corpse flower. The second you walk into its greenhouse, its smell smacks you across the face. It’s very strong. The plant also heats up when it blooms, which spreads its smell farther.”
This tall, robust plant – that’s actually known as titan arum (Amorphophallus titanum), native to the tropics of Sumatra, Indonesia – has an almost cult-like following, in part because it only blooms for a day or two, every few years. Some may not even flower more than once a decade. But it’s when it does open up, albeit briefly, it emits a pungent stench that – for humans, at least – has been described as everything from hot garbage to rotting flesh.
Naturally, this serves a purpose – it’s a surefire way to attract pollinators like flies and carrion beetles. But despite the smell bringing all the bugs to the yard, it’s not all rotting meat for the beloved corpse flower.
While the endangered plant is increasingly threatened by habitat destruction and climate change, biologists from Northwestern University and the Chicago Botanic Garden have uncovered that it’s facing another huge challenge for survival: Poor record keeping.
The scientists discovered this potentially fatal flaw while putting together the genetic ancestry of 1,200 corpse flowers currently living in 111 gardens and other institutions around the world. They found so many holes in the data collected on these plants that conservationists undertaking breeding programs inadvertently narrowed the genetic pool in the process. The researchers found that of the plants they studied, 24% were direct clones and 27% were the offspring from two closely related corpse flowers. As any biologist, ecologist or zoologist will tell you, this can be a death sentence for an entire species.
And much like in the animal kingdom – yes, including in humans – inbreeding among small populations results in a suite of evolutionarily disadvantageous traits that hamper health and survival.
“There are many risks associated with low genetic diversity,” said Murrell, who led the study. “Decreasing genetic diversity over time leads to a decrease in fitness. Generally speaking, inbred plants might not produce as much pollen or might die right after they flower. One institution reported that, possibly as a result of inbreeding, all their corpse flower offspring were albino, so they didn’t survive because they didn’t have chlorophyll to photosynthesize.
“The population as a whole also doesn’t have the variation it needs to survive. So, if a disease or pest affects plants that are all genetically similar, all plants in that population are more likely to suffer. We don’t think people are consciously making the choice to inbreed their plants. They just don’t know what they have because the data are incomplete.”
What’s more, the corpse flower is classed as an “exceptional plant” – no, not because of its stench – as its seeds can’t be preserved in seed banks, a feature of just a few species in nature. This is because once the seeds have been dried, which is necessary for storage, they’re essentially useless.
And they have yet another challenge: the plants in the world’s “living collections” – like the ones studied here – are high maintenance.
“The female flowers open first, and then the male flowers open later,” Murrell said. “So, the female flowers are no longer viable by the time pollen is produced. The plant also blooms rarely and unpredictably. It could go seven to 10 years without blooming. Then, when the blooms do open, the female flowers are only viable for a couple hours. With that limited time to pollinate, conservationists scramble to use whatever they have on hand. That might be pollen from a previous flower on the same individual, which results in inbreeding.”
When Murrell sent out requests for records on the 1,200 individuals, she received a mess of handwritten notes, prose, lists and spreadsheets. Lacking was essential information on the plants’ origin, parents, characteristics, health and propagation history.
“The highest rate of missing data occurred when plants were transferred to new locations,” Murrell said. “The plants moved, but their data didn’t move with them. So, records easily got lost over time as plants moved around.”
Of the final 1,188 plants in the assembled dataset, 287 were clones, and fewer than one-third were the offspring of unrelated individuals. Further DNA sequencing revealed that there was low genetic diversity and significant inbreeding in all collections.
So, why does this matter? There’s only an estimated 162 corpse flowers left in the wild, and inbred specimens hamper reintroduction efforts.
“The population needs variation to survive,” Murrell said. “If nothing changes, it could inbreed itself into extinction. That’s why it’s really important to keep consistent, standardized and centralized data. Not keeping data has clear conservation implications. In the meantime, our study provides valuable information about relationships among existing collections, which can be used to determine which crosses might be most successful.”
It would be such a shame to lose this enigmatic, extremely smelly, wonder of nature – all because paperwork is a pain. However, the corpse flower is not dead and buried just yet; this study’s findings highlight the urgency of creating a global genetic database and for international cooperation in finding new ways to prevent inbreeding.
Meanwhile, if you’re curious about the molecular inner-workings of how this plant produces such an offensive smell, scientists at Dartmouth unlocked the mystery of it in a great study published last November. And you can watch a time-lapse video of a corpse flower blooming at the United States Botanic Garden in Washington, DC below (which, fortunately, does not come with smell-o-vision).
Corpse Flower Bloom Time Lapse – USBG
The study was published in the journal Annals of Botany.
Source: Northwestern University
