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| Prasophyllum morganii, the mignonette leek orchid Photo: Tobias Hayashi |
Two recent discoveries prove the resilience of some plants in spite of near constant threat of extinction from humans and human induced climate change. First, in Australia's Victoria state is the story of an orchid supposedly driven to extinction since the 1930s, Prasophyllum morganii, the mignonette leek orchid.
Described in the 1930s as a small terrestrial herb with a single flowering stem “densely crowded with flowers”, its only recorded population was found on private land near Cobungra, Victoria, and consisted of fewer than 15 plants.
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After the Australian black summer bushfires in the summer of 2019-20, the federal government funded a $500,000 bushfire recovery project to survey key wilderness areas in East Gippsland, the alpine areas of New South Wales and Kangaroo Island in South Australia for 14 species of nationally threatened orchids affected by the fires.
Scientists surveyed the populations, developed collections of seeds and also collected species of an orchid first found in the Kosciuszko National Park in 2000 and called the Kiandra leek orchid, or Prasophyllum retroflexum.
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| Dr. Noushka Reiter holds baby mignonette leek orchids, which are no longer considered extinct after a naming mix-up. Photo: Joe Armao |
Through an exhaustive process of comparison between this Kiandra leek orchid, and 90-year-old specimens of the “extinct” mignonette leek orchid that had been pressed and preserved in the National Herbarium of Victoria at the Royal Botanic Gardens, scientists established the two species were actually one and the same.
“We compared the floral characters – how wide they were, whether they had little bumps on them – it was weeks and weeks of measurements,” said senior research scientist Noushka Reiter, from the Royal Botanic Gardens.
Essentially, it meant the Kiandra leek orchid doesn’t exist. The person who found those specimens and named them didn’t realise they were actually the mignonette leek orchid which, though not extinct, is still critically endangered.
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| Dr. Bronwyn Ayer doing seed collection from the mignonette leek orchid. Photo: Tobias Hayashi. |
A group of four scientists, including Dr Reiter, have published a paper in the scientific journal, Phytotaxa, that outlines how they measured 51 morphological traits on collected species, compared them with the herbarium specimens and concluded that the two “are conspecific [the same species]”. It just shows it’s really important to do that comparison work and to have that bank of specimens to compare with,” said Dr Reiter. “It’s not the kind of thing that happens often.”
Co-author Bronwyn Ayre said the discovery would not have been possible without specimens stored in the National Herbarium.
“It was amazing to be able to compare flowers collected over 90 years ago, to ones we just collected ourselves,” Dr Ayre said.
Victoria’s State Botanical Collection contains 1.5 million dried plant, algae and fungi specimens.
With a small living population of mignonette leek orchids now identified in Victoria and NSW, but fewer than 500 plants existing, the scientists have collected seeds and are growing baby orchids at the botanical gardens in Cranbourne.
All orchids rely on mycorrhizal fungi to germinate, so researchers have also isolated the specific mycorrhizal fungi for the mignonette leek orchid and learnt how to culture it in the lab to get the seeds to germinate.
All the 14 nationally endangered orchid specimens surveyed by the bushfire recovery program are now being propagated at the botanic gardens.
Then a world away, in Ecuador, came the story last fall that another plant long considered extinct had been found on a private reserve in a rainforest remnant. Nigel Pitman was one of the first to report the new discovery on Twitter:
A flower was named after its own extinction — then it was rediscovered
Botanists found patches of rainforest in Ecuador long believed to have been wiped out
For decades, the Centinela rainforest in Ecuador was the subject of tropical botanists’ dreams. The problem was it didn’t exist anymore.
The slice of forest was said to be among the most biodiverse eight square miles recorded in the world, containing 90 species of plants that couldn’t be found anywhere else. But, according to the scientists who had intensely studied the rainforest and presented their findings three decades ago, Centinela and all its biological treasures had been cleared and replaced with plantations, along with more than 90 percent of western Ecuador’s rainforests.
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| The Gasteranthus extinctus was found growing next to a waterfall in a private reserve in the Centinela region in western Ecuador. (Photo: Riley Fortier) |
The tragedy even got its own name. A “centinelan extinction” came to describe the sudden annihilation of a species before it could be known or understood. One plant, spotted in the Centinela rainforest before it had reportedly been wiped out, encapsulated the concept — a bulbous neon-orange flower whose name preordained it as lost forever: the Gasteranthus extinctus.
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| Remnants of the Centinela rainforest remain. Photos: Nigel Pitman |
Now, a group of botanists who have since set foot in the Centinela rainforest says sizable pockets still exist, despite the claims of their predecessors — and they have found the flower presumed to be extinct for decades, shining like neon-orange spotlights through the rainforest’s foliage.
“We walked closer and closer, and we just knew that was it because of the color of the flowers,” Dawson White, a botanist with Chicago’s Field Museum who ventured into the Centinela rainforest in search of the flower said.
In the end, the G. extinctus wasn’t very hard to find. After the group realized enough of the forest existed to support diverse plant life, it searched several pockets and found the flower within hours, according to a study published recently in the journal PhytoKeys. SEE: Rediscovery of Gasteranthus extinctus L.E.Skog & L.P.Kvist (Gesneriaceae) at multiple sites in western Ecuador
“We found it just about everywhere,” wrote Nigel Pitman, a botanist with the Field Museum and a lead author of the study.
While the study focuses on the rediscovery of G. extinctus — a finding that grabbed headlines — Pitman said it was more remarkable that his team had found existing pockets of rainforest at the Centinela ridge and can challenge the widely held belief that the rainforest had been almost entirely destroyed.
“Everything that made me and my colleagues passionate about saving tropical forests was this story of a place that was celebrated and mourned at the same time,” Pitman said of the Centinela rainforest, “because it had so much amazing stuff in it — and then it was suddenly gone.”
But “it isn’t all gone,” he added. “We did find patches of forest, and there is still an opportunity to preserve it.”
In 1991, botanists Alwyn Gentry and Calaway Dodson, then leaders in their field, published a paper titled “Biological Extinction in Western Ecuador.” It found that the vast majority of rainforests in western Ecuador, a particularly biodiverse area the size of North Carolina, had been cleared to make way for banana, coffee and cacao plantations — a situation that Pitman and White said has only worsened since that paper was published.
But a portion of the paper focused on a particular foothill of the Andes — the Centinela ridge, a cloud forest that contained 90 plant species that existed there and nowhere else, an unusually high number of endemic plants, White explained.
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| Part of the team that rediscovered Gasteranthus extinctus traverses steep ravines in the forests of coastal Ecuador in search of rare plants. From left: Washington Santillán, Sr. Hermogenes, Alix Lozinguez, and Nicolás Zapata. Photo: Thomas L. P. Couvruer. |
“Many of these species at Centinela are strikingly beautiful and quite unlike any known” plant groups, the authors of the 1991 study wrote.
Yet in the same beat, they delivered a gut punch: “The main ridge is now deforested, and an undetermined number of these species are now extinct.”
Pitman, who was in college when the paper was published, said the story that Gentry and Dodson told was “foundational” for biologists in his field.
“We talked about it all the time,” Pitman said. “It was so inspiring and so compelling to us that we just sort of took it as gospel.”
In his 1992 book “The Diversity of Life,” biologist Edward O. Wilson took the Centinela story a step further, using it as a symbol of the “silent hemorrhaging of biological diversity” and coining the term “centinelan extinction,” which came to describe the destruction of species before they could be discovered or fully studied.
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| Scientific team presses and preserves the plant specimens collected during the day searching for Gasteranthus extinctus. Photo: Riley Fortier. |
It was from those narratives of Centinela that the Gasteranthus extinctus — a bright orange flower that had once been observed on the ridge — received its name, according to the study published Friday. Pitman said he did not know of any other plant whose scientific name contained the word “extinct.”
Yet around the time the G. extinctus received its name — nearly a decade after Dodson and Gentry’s paper published — the Centinela narrative began to show cracks. Plant species the authors had said existed only in Centinela were discovered elsewhere. Botanists who visited Centinela reported that small patches of forest remained in the area, although no one had sought to fully study them, according to Pitman.
So several years ago, Pitman and White set out to test what had previously been reported about Centinela. What they found were pockets of diverse wilderness large enough to get lost in — with some containing howler monkeys and cascading waterfalls.
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| Workers in remnants of the Centinela Rainforest. |
“The fact that it still has these large monkeys is an amazing sign of the health of this forest,” White said. “Some other places that we’ve visited, gosh, they could be national parks.”
And shining through the forest’s low-lying foliage and along rock walls — and even in cattle pastures bordering the forest fragments — was the flower that was supposed to be extinct. Pitman said he had been using a line drawing to identify the flower. So “when I got close enough to see it, the sensation was that the line drawing had come to life.”
White said the feeling of seeing the flower, which in many ways had come to symbolize the story of Centinela, was “just elation and really a sense of purpose.”
The scientists are now using the discovery of the large forest fragments and the Gasteranthus extinctus to push for conservation, as they said deforestation of western Ecuador continues. And while at times White can’t avoid defaulting to a sense of hopelessness looking over the largely deforested western Ecuadoran landscape, he said, their most recent discovery calls for optimism.
“Because every win is a win,” he said. “And right here we are saving something that is demonstrably unique.”
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