In Australia, he went plant hunting by helicopter and waded in crocodile-infested waters to watch a water lily bloom. In Mauritius, he grabbed a plant specimen off the ledge of a cliff. Last month, while looking for lilies in a tributary of Colombia’s piranha-packed Orinoco River, he jumped from plank to plank in the pitch dark at 4 a.m. to get to a floating pontoon.
“It’s not that I am that daring,” said Carlos Magdalena, a research horticulturalist at the Royal Botanic Gardens, Kew, in London. “These situations just arise, and they are not like Superman extreme. Sometimes it’s more Peter Sellers than Indiana Jones.”
Mr. Magdalena’s main responsibility at Kew Gardens is tending tropical plants. But he is also known as “the plant messiah,” as anointed by a Spanish newspaper in 2010, for his work rescuing several plant species from the brink of extinction. That work has earned him enormous respect in the field of botany and made him somewhat of a celebrity in the horticulture world.
His renown only grew when David Attenborough, the British doyen of nature documentaries, repeated the “plant messiah” tagline at the 2012 premiere of one of his films, which featured a scene of Mr. Magdalena propagating the pygmy lily.
The attention, especially from a figure as venerated as Mr. Attenborough, initially dismayed Mr. Magdalena. “Imagine what happens when the God calls you the messiah,” he said, standing outside one of the graceful greenhouses at Kew Gardens.
It is appropriate that Mr. Magdalena’s star moment in the documentary showed him working with lilies, the plant closest to his heart and the first one he grew as an 8-year-old on his parents’ finca, a plot of land in the Asturias region of northern Spain.
The pygmy lily was what helped bring Mr. Magdalena, 51, to broader attention.
The smallest water lily in the world, Nymphaea thermarum, its flower about the size of a fingernail, had become one of Kew Gardens’ prized possessions. In 2014, it was stolen from the gardens. The thief was never caught, but Mr. Magdalena, who had cared for the tiny plant, made the media rounds, explaining the rarity of the flower, native to Rwanda.
Since then, he has embraced the role of serving as a megaphone for the silent plant kingdom, a showman as exuberant and colorful as some of the tropical flowers he cultivates.
“Plants don’t speak. Plants don’t cry. Plants don’t bleed,” he said. “So I’ve decided to speak for them.”
The youngest of five children, Mr. Magdalena was an indifferent student, but devoured his parent’s gardening encyclopedia, reading it 12 times by the time he was 8. “I preferred living with the ants,” he said of his childhood.
His mother grew flowers. His father farmed as a hobby. And nature became central to their son’s worldview. His grandfather took him around on a donkey, pointing out the names of plants and animals, and it’s a habit he inherited.
“I’ve never outgrown the stage when children point at nature,” he said.
Just as his mother would sometimes force her husband to stop the car in the middle of the road if a plant caught her eye, Mr. Magdalena can’t help but do the same, sometimes to the impatience of his Kew Gardens colleagues.
“It’s quite a sight to watch him jump into a ravine or creek looking for plants, water up to his neck, happy as can be for hours,” said Christian Ziegler, a photojournalist who has worked with Mr. Magdalena on some of his global quests to find endangered flora to nurture.
With few work opportunities in Asturias, where he managed a bar, Mr. Magdalena moved to London in 2001. If Britain was different in many ways from home, the two places shared something in common: damp, green landscapes.
At first, he took hospitality jobs. Then, one day in 2002, he visited Kew Gardens, and the trip turned into an origins story as uncommon as some of his cherished plants.
As he peered through the condensation clouding the windows of a tropical nursery, he dreamed that “all those plants could be at my disposal.”
He sent an inquiry email to Kew’s School of Horticulture, and the principal invited him for a visit. The two hit it off, and Mr. Magdalena, despite his lack of professional or academic qualifications, landed an unpaid internship.
Four months later, he earned a temporary job as assistant propagator inside the nursery of his dreams. “Time to show off,” Mr. Magdalena said.
The first plant Mr. Magdalena saved from extinction was the café marron, or Ramosmania rodriguesi, a tree that grows to about the height of a man and has distinctive white, star-shaped flowers. Endemic to the Mauritian island of Rodrigues, no living specimen had been seen since 1877 — until a schoolboy found another some 45 years ago.
A cutting was sent to Kew Gardens, and although the clone flowered, the plant did not produce seeds. Until Mr. Magdalena arrived.
In what has become part of botany lore, he spent five months intensely studying the plant. After much experimentation and 200 attempts at pollination, he succeeded in coaxing forth seeds, around 20 of which were sent to Mauritius, where the pretty flower is now seen once again.
“Carlos delivers,” said Dr. Alex Monro, a lead scientist at Kew Gardens.
While Mr. Magdalena eventually earned a diploma from the Kew horticultural school — to him, “the Oxford of gardening” — he is known for relying less on traditional techniques than for more unconventional approaches.
To help save the pygmy lily, he borrowed seeds from a botanical garden in Germany. While these seeds germinated, they quickly died. “An extinction awaiting to happen,” he said.
Mr. Magdalena tried everything, growing the seeds in acid and alkaline water, and experimenting with light and temperature. Nothing worked.
One night as he watched the water for his tortellini bubbling, he wondered if the difficulty germinating the tiny lily had to do with the amount of carbon dioxide the plants were being exposed to.
“Plants need light, water, nutrients — and they need carbon dioxide, too,” he explained.
As he prepared his dinner, he remembered that the water lilies in their native habitat in Rwanda grew in a shallow stream, and that there is much more CO2 above water than below, so he changed the depth of the water he was using in his experiment in a bid to get them more of the gas. It worked.
While his initial renown may be thanks to mini lilies, what might be his biggest accomplishment falls on the other end of the size spectrum.
Giant water lilies, of the genus Victoria, are a major part of Kew Gardens’ summer displays, displayed in a dedicated green house.
In 2007, Mr. Magdalena’s low-paid job included caring for the only two known species — Victoria amazonica and Victoria cruziana.
The plants were named after a newly crowned Queen Victoria, to secure her patronage for Kew Gardens.
As he tended to the enormous plants, Mr. Magdalena became increasingly obsessed and would spend nights researching them online, which is where he stumbled upon a photo of the strangest Victoria leaf he had ever seen and, suspecting it was an unknown species, had to learn more.
He contacted the photo’s owner, who had found this anomalously enormous lily in the Amazonian ponds of the Beni region of northern Bolivia and had transplanted cuttings from it to a man-made pond in Santa Cruz, Bolivia.
A few years later, Mr. Magdalena found himself in Bolivia, teaching a local community how to grow Brazil nuts more effectively. He took a couple days off, ventured to the man’s pond to see the mysterious, humongous lilies for himself and persuaded the owner, with an assist from the Santa Cruz Botanical Garden, to donate a few seeds to Kew Gardens.
Back in London, as the Bolivian seeds started growing with leafs and flowers that looked different from what he was used to, he began to strongly suspect he was looking at a third, unnamed species of Victoria.
He proceeded carefully in his investigation, keenly aware it was unusual in the field of botanical science that “a gardener like me,” as he said, might help identify a new species. But his observations ultimately convinced him, and the scientific community agreed.
On July 4, 2022, Kew Gardens announced the discovery of a third Victoria lily, naming it Victoria boliviana Magdalena & L. T. Sm., the second name recognizing the contribution of Lucy T. Smith, a botanist and illustrator at the gardens who had shared his conviction this was a new species.
The media attention was intense.
“I am still doing interviews. Yesterday, it was German television,” said Mr. Magdalena, who believes more giant water lily species may be awaiting discovery.
“My beloved nenúfar,” he said, using the Spanish for water lily.
Although the “plant messiah” moniker had originally bothered him as pretentious, he has since embraced it — “It’s just such a good handle” — using it as the title of a book.
“In Spain, the messiah is like being Jesus, which I am not,” he said. “For Anglos, it’s more like someone with a mission, someone who has things to say in the fight for a cause.”
His celebrity and outspokenness have not always sat well within the genteel world of gardening. But Mr. Magdalena said he doesn’t care about rubbing people the wrong way and has no plans of lowering his voice in championing the plant world, which he wants to imbue with the same charisma enjoyed by the animal kingdom.
“We need to stop thinking that plants are just greenery in the background,” he said, pointing at a blooming Titan arum. It is also known as the corpse flower, renowned as the smelliest of all plants, its rotting stench an evolutionary strategy to attract pollinators. “How cool is that?” Mr. Magdalena said.
His voice then shifted into a more serious tone, talking about the race to save as many plants as possible before they disappear forever.
“There are still more than 100,000 threatened species that are sitting at the bar having their last beer,” the former bartender said. “I have nothing else to do. Just this.”