Their mission: save Minnesota's rare orchids before it's too late
Head slightly bent, David Remucal scanned the forest floor duff for a tiny, white-veined plant with the consistency of rattlesnake skin.
An hour later, he found it — an orchid species known commonly as rattlesnake plantain, a fragile beauty hidden beneath moss and pine needles.
Remucal, though, hadn't traveled hours north just to admire it. Reaching down, he pinched off a tiny seed capsule, all that remained on the orchid's flowering stem, and emptied it into a small bag.
"That's the seed," said Remucal, curator of endangered plants at the Minnesota Landscape Arboretum. "Can't even see it very well in my hand. It's basically dust."
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It was enough. Finding the rattlesnake plantain seed was a vital step in Remucal's quest to save it and other rare orchids native to Minnesota. His goal is to build a seed bank of all 48 orchids in the state, including the showy lady's slipper, Minnesota's state flower.
It's part of a broader effort led by the Smithsonian Institution to bank the genetics of the more than 200 orchids in North America — more than half of which are endangered — before they're gone.
Researchers often describe orchids as the plant equivalent of the canary in the coalmine: their deaths can be a warning of environmental changes likely to be exacerbated by climate change.
"A lot of orchids are the first species to disappear from a landscape," Remucal said, because they're extremely sensitive to changes in habitat and the loss of pollinators. "We could be losing a lot of these landscapes over the next 50 years, so we could be losing a lot of these orchid populations."
While saving the species is important work, it takes lot of patience as evidenced by Remucal's search for the rattlesnake plantain at the University of Minnesota's Cloquet Forestry Center.
Minnesota's native orchids can be really hard to spot. That's in part because they're really rare. More than 20 percent of the state's native orchids are considered threatened or endangered.
The seed is being kept in new freezers at the arboretum, but more data is needed on just how long orchid seeds can be stored and remain viable.
Really, little is known about many of Minnesota's native orchids. The brilliant tropical varieties of orchid have been exhaustively studied and propagated, but the majority of orchids native to North America have been largely ignored by scientists to the point where researchers don't even know how to grow many of them.
So the second part of the arboretum's project, which is funded by a grant from the state's Environmental and Natural Resources Trust Fund, is to attempt to propagate orchid species in the lab.
"What I'm doing is transplanting orchids that have germinated," explained research volunteer Laurel Krause as she bent over tiny seedlings in a sterile hood at the arboretum's lab in Chaska.
The roots are translucent, several inches long. "It's sort of like a spider, a big daddy long legs," said Krause.
This plant is from seed Remucal gathered nearly a year ago. But the plant itself is still tiny, a pale yellow-white tip not even a quarter of an inch tall. It might take six years or more before it flowers.
Krause is growing the fragile plant, not in soil, but in a jello-like substance with a potato stuck in it to provide nutrients for the plant to grow.
Orchids aren't like annuals you plant in your garden. You can't just throw seeds in the soil and have flowers in a couple months. Remember the seeds Remucal gathered?
"They're called dust seeds, because they're so tiny," explained Dennis Whigham, a botanist at the Smithsonian Environmental Research Center in Maryland.
Unlike most plants, an orchid doesn't store food in its seed to nurture the embryo. "Most plants when they package their babies inside a seed," said Whigham, who's leading the nationwide charge to preserve orchids. "They put some food in there."
So an orchid, he continued, has to get its food from somewhere else. "And the only answer is it has to get carbon from someplace, and it gets it from fungi."
It turns out about 90 percent of plants have this give and take relationship with fungi, underground. They use each other to get the food they need. Not orchids. Rather than a symbiotic, two-way interaction, "It seems to be a one-way interaction," said Whigham. "What happens, the orchids eat the fungi."
Yes, it turns out a flower celebrated in poetry and song for its delicate beauty is really a voracious predator.
In fact, Whigham said, some orchids have evolved to not even have to use photosynthesis to survive. Some species have been found to survive for 25 years underground, living off fungi, before finally popping up above ground to flower and reproduce.
Whigham is leading an effort called the North American Orchid Conservation Center to create an orchid seed bank as well as a bank of fungi that will eventually be stored using liquid nitrogen.
In the long term, the goal is to be able to plant orchids along with the appropriate kind of fungi they need in the soil.
But first, they need the seeds. So far in Minnesota researchers have collected that tiny dust seed from about 30 of the state's native orchids.
"I want to get ahead of the game," said Remucal, "and make sure that we have those seeds so that we can save these species."