- Planet Possible
Cultivating the world’s largest, stinkiest flower is no small task
For decades, the Rafflesia has resisted attempts to grow it outside Southeast Asian rainforests. But one Indonesian botanist’s efforts have finally blossomed.
One of the world’s freakiest floral phenomena starts from a seed the size of sawdust beneath the bark of a woody vine. After months or years (no one really knows), a parasitic bud may emerge, a golf ball–sized knob that’s hardly distinguishable from its host, the Tetrastigma vine. If the bud makes it to the next stage, it’ll upsize into a cabbage-shaped bulge. The grand finale is the monstrous bloom Rafflesia, a blood-red flower sporting polka dots and emanating a stench of rotting flesh.
The specter of the flower is disturbing—and soon, its fate might be too. The roughly 30 known stinky species in the Rafflesia genus, found only in Southeast Asian rainforests, are threatened by habitat destruction and illegal harvest for their questionable medicinal benefits. Several species are critically endangered.
As a parasite, Rafflesia restricts its numbers so as not to overwhelm its hosts, says Sofi Mursidawati, a botanist at Bogor Botanical Gardens on the island of Java. But in the face of human-driven pressures that imperil its existence, Rafflesia—also known as the corpse flower—is arguably its own enemy when it comes to self-preservation.
When animals are threatened with extinction, conservationists rush to breed the last remaining individuals in captivity. In this case, Mursidawati is the first botanist to have reliably cultivated Rafflesia flowers far from their rainforest habitats. She’s eager to share her techniques to unlock the secrets of this natural curiosity before it disappears.
Members of the Rafflesia genus are breathtakingly bizarre. For one, the flowers are inexplicably immense, says Mursidawati. Rafflesia arnoldii holds the record for the world’s largest individual flower, at over three feet in diameter and 20 pounds.
There are other botanical behemoths, and even other foul-smelling ones: Species of Amorphophallus, found in Asia, Africa, and Australia, are also called corpse flowers. The most elusive of nature’s floral stink bombs is Rafflesia, and like the odors of its peers, its stench is an irresistible lure to pollinating carrion flies but off-putting to most humans.
By botanical definition, Rafflesia barely qualifies as a plant. It has no stems, roots, or leaves. It lives completely off its host, having jettisoned its gene for photosynthesis millions of years ago.
“The puzzle just keeps getting more complicated,” says Jeanmaire Molina, a plant biologist at Long Island University in Brooklyn who made the missing gene discovery in 2014. “It has been quite challenging to study the Rafflesia, let alone conserve it.”
The parasite’s complicated lifecycle and mysterious biology harrow the scientists who want to stave off its extinction.
Flowers, the reproductive hub of plants, usually have both the male pollen-producing and female pollen-receiving parts. Rafflesia individuals are single-sex, possessing just one half of the equipment for pollination. For fertilization to occur, two flowers not only have to bloom simultaneously, but one must be of each sex—and they must bloom within a mile of each other, close enough for pollinators to ferry genetic material between them. Further complicating matters: Blooms last for less than a week, so the window of time for pollination is a mere blip compared to the Rafflesia’s lifespan of several months or years.
Mursidawati has never successfully hand-pollinated Rafflesia, nor has she germinated one from wild seeds. Instead, she has developed an alternative method: grafting tissues from a Rafflesia-infected vine with another host plant.
Slow bearing fruit
Mursidawati’s career in Rafflesia botany started in 2004, when she returned to Bogor Botanical Gardens after completing her graduate studies abroad. Brainstorming project ideas, she settled on her supervisor’s suggestion to cultivate Java’s native Rafflesia patma in the nursery. For 70 years before her, other botanists had tried and failed.
When she started, “I don't think there was anybody who was willing to work with Rafflesia because of the difficulties,” she says. “Everybody also told me that it was impossible.”
On top of improving tried-and-tanked techniques, Mursidawati also tinkered with a grafting method previously applied to mountain ash plants in the United Kingdom.
She first collected wild Rafflesia samples from the Pangandaran Nature Reserve, an eight-hour drive from Bogor. Reaching the plants took another three hours of hiking. She brought back Rafflesia seeds, root cuttings of a grape-vine-like Tetrastigma adorned with Rafflesia buds, and, in her earliest days, an entire host plant uprooted from the rainforest. Next, she ran parallel tests of seed planting, resurrecting the fully grown host plant, and bandaging the root cuttings to thriving Tetrastigma in the nursery.
None of the original buds on her Tetrastigma samples survived. In 2006, a new bud appeared on one of the host plants, only to succumb two months later to sunlight overexposure when a hurricane blew a hole in the overhead canopy.
Four more years would pass before Bogor Botanical Gardens welcomed its first Rafflesia flowers. A male debuted on its grafted Tetrastigma, and a year later, two females sprouted on the transplanted host. Mursidawati named her females Margaret and Elizabeth after the British Royal Family.
In the last decade and after hundreds of trials, Mursidawati has hand-raised 16 Rafflesia from bud to bloom. She acknowledges that her efforts—while a large step for Rafflesia botany—are a small step for conserving the species. The bud mortality rate is 90 percent. She hasn’t been able to grow any other species such as the arnoldii, which is found not far away on the next island over, and so easier to gather.
So far, the flowers in her garden have had unfortunate timing: They haven’t bloomed synchronously so that pollination can occur; consequently their seeds are nonviable. That means the long lineages of the Rafflesia borrowed from the wild will have spawned their last generations in Mursidawati’s garden.
The right conservation strategy
Though Mursidawati’s efforts are an important back-up for the preservation of the species, overemphasis on cultivation will distract from the real work of protecting Rafflesia in its natural habitat, says Zulhazman Hamzah, an ecologist at the University of Malaysia, Kelantan. His environmental campaigns spurred the government to set up federally-protected rainforest sites in West Malaysia after his team found Rafflesia there.
Other researchers contend that cultivation will boost the Rafflesia’s shot at survival and increase the accessibility of this natural wonder for the rest of the world. “It doesn't really matter where it grows, as long as it promotes conservation of that organism,” Molina says. More people will want to contribute to Rafflesia preservation once they learn to appreciate the curiosity she calls “the panda of the plant world.”
In many ways, the plant inspires similar calls to action as the beloved bear. Like the panda, the floral giant is a tourism magnet and a source of revenue for the locals. It’s also one of Indonesia’s national flowers. To lose the Rafflesia, Mursidawati says, would be to lose part of her national identity.
It takes a special kind of mental fortitude to cultivate flora as finnicky as Rafflesia. Musidawati says that among the hundreds of Tetrastigma vines crisscrossing the floor and climbing the fences of the nursery, only three have ever managed to spawn Rafflesia flowers. She jokes that the host vines, like her, are probably due for retirement.
Now that Mursidawati has finished training a recruit on Rafflesia cultivation to take over her work, she can sleep a little easier. She still tends to her Rafflesia buds every few days, and although she normally works alone, she’s never lonely. Her plants are “easier to talk to than humans,” she says—and she ends each of her one-sided chats with a personalized prayer, her hope burning undiminished.