Inside a 40-year effort to protect a tiny wild orchid

Michael Piantedosi pulled his car onto the shoulder of a two-lane highway, and parked next to a patch of woods that looked utterly ordinary — another forest like so many others lining the roads of rural New England.

But these woods held a secret: a cluster of rare wild orchids, called small whorled pogonia, that conservationists are trying to save. There are only about 3,000 of these orchids in the world, and Maine and New Hampshire are home to some of the largest populations.

This particular patch has about 300 plants, making it one of the largest clusters on the planet. Piantedosi, who directs conservation at the nonprofit Native Plant Trust, is so concerned about poachers that WBUR agreed to keep the location secret.

New England is home to about 70 species of wild orchids, some of them rare, and many of them threatened by habitat loss and climate change, in addition to poachers. The small whorled pogonia, or Isotria medeoloides to botanists, is no different.

"It's globally threatened," Piantedosi said. "So it's really crucial as just another piece of biodiversity in this forest."

About 100 yards into the woods, Piantedosi stopped. He pointed to a tiny plant, just a few inches tall, with five green leaves and a pale green flower the size of a pinkie fingernail. The secret orchid.

It's a not a showy flower, that's for sure. It's a little surprising that that poachers would want to steal it.

"People are really into orchids," Piantedosi said. "Especially when something is considered rare."

Tim Johnson, CEO of the Native Plant Trust, describes himself as an "orchid person in recovery." This was his first time seeing the small whorled pogonia, and he was smitten.

"I think that orchids have such gravity and personality," he said. "Even our more subtle orchids really just pull at my heartstrings and make me giddy."

There are about 30,000 species of orchids in the world, and about about half of those are threatened, according to Abby Meyer, executive director of Botanic Gardens Conservation International-US, a global network of botanic gardens and seed banks.

"It's concerning," she said.

Many orchids are exquisitely adapted to a specific habitat and sensitive to small environmental changes. This makes them good early indicators of new diseases or invasive species. But it also makes them especially vulnerable to a long list of threats, including the effects of climate change, development, soil degradation, excessive rain and invasive earthworms.

"I'm a little concerned about our population," said Grace Glynn, Vermont's state botanist. The small whorled pogonia was thought to have disappeared from Vermont, until it was re-discovered in 2022. There is now one known population in the state, with nine plants at last count.

"We're vulnerable to losing the species from the state," Glynn said. "You get one freak flood event, you get a couple years of heavy deer browse, and that really knocks back the population."

The orchids in the secret patch I visited with Piantedosi were discovered in 1982, and experts from myriad state agencies and nonprofits have monitored it every year since 1986. In the 1980s, plant experts noticed the orchids seemed to grow better in places with more sun — under trees decimated by hungry caterpillars, for instance, or near power lines where workers cut back tree limbs for safety. So they tried an experiment: thinning the tree canopy by 25% over a section of forest to let more sunlight through.

It seemed to work. The number of orchids growing in the test plot more than doubled in the six years following the canopy thinning, and bore more flowers and seeds as well.  The experts also found that orchids in the site without canopy thinning seemed to have less fruiting and flowering over time. Still, Piantedosi called the results "inconclusive," because it isn't known whether the additional sunlight was responsible for the increased growth.

"Opening up a canopy is a dynamic process," Piantedosi said. It heats up the soil and changes the leaf litter, possibly altering an underground fungus that is crucial to this orchid's survival.

A similar situation in Virginia, where a large tree died naturally, suggested that an uptick in this fungus — rather than sunlight per se — may be the key to more bountiful orchids. Additional experiments are ongoing, but they take time. The small whorled pogonia can remain dormant for as long as 10 years, requiring patience from researchers.

The canopy thinning experiment also raised some thorny questions. How much should experts intervene to help these orchids — or any wild plant? At what point are the plants no longer wild? These are questions Piantedosi said he grapples with all the time.

"I think we’re really aware of that line. It’s different for every species and every location," he said, but the goal is to keep these orchids wild. "We would like for these plants to have management enough so that they can reproduce on their own irrespective of our intervention."

Outside the forest, experts have not yet been able to grow full whorled pogonia plants from their seeds. And even if they could, finicky orchids like this don’t usually transplant to new locations well. So the plants' best chance at survival, right now, is to thrive in their native habitats.

"We need to make sure that we're working towards conserving those plants where they are," said Glynn. She's keeping a close eye on Vermont's nine small whorled pogonias but not planning any interventions.

"We want to help this species persist, but we also want to be humble," she said. "We don't want to assume that it needs anything of us."

To some, all this work and worry over a tiny, rare plant might seem a bit odd. Most people wouldn't recognize a small whorled pogonia if it was growing on their lawn, and wouldn't miss it if it went extinct. Or, would they?

After all, a tiny orchid is not just a tiny orchid — it's part of a complex ecosystem. And even experts don't know exactly what role it plays.

"The way I like to describe ecosystems, it's sort of like a tapestry," Meyer said. "If you start pulling one thread at a time out of the tapestry, you start to see holes, you start to see through the tapestry. That's how the fabric of a habitat works as well."

Piantedosi’s team is weighing whether to thin the canopy again to help the plants flourish. He thinks they will likely take this step. Thriving plants in a healthy ecosystem may be better able to survive threats like flood or drought, or even migrate northward if climate change necessitates it.

"I often quote Aldo Leopold: The first step in intelligent tinkering is to save every cog in every wheel," said Piantedosi "Ultimately, nature is a system we don't fully understand."