In a private wooded area on the expansive property that houses Longwood Gardens, a unique orchid has quietly taken root.

What makes this fruit-bearing flower, not-so-commonly known as Cyrtosia septentrionalis, so unique is that Longwood Gardens has never imported the plant, according to their records.

There is no evidence of anyone ever ordering the Japanese orchid, which is impossible to cultivate in normal nursery settings because it is an awfully picky little thing. Over decades of orchid displays and dozens of different species, there is no trace of this particular species coming to the former farm owned by Pierre du Pont in Kennett Square.

"It's totally unprecedented. This has never been found in the United States," said Peter Zale, Longwood's associate director of conservation, plant breeding and collections. "I said, 'It can't be true.' How on earth did that thing get into the woods back there? I had to go see it myself."

And he did. And it was the same type of orchid he had been featuring in presentations about Longwood's native orchid program, as an example of a non-native orchid that was just too darn picky to take root.

Peter Zale's orchid blog:Phantasm of the Forest

How it got there and how long it has been growing remains a mystery, Zale said. But so far, it doesn't seem to be a threat.

"We monitor the property for invasive species all the time and, as of now, we don't think this is showing invasive potential," he said. There are about 10 clumps of the orchid growing in a part of the gardens closed to the public, in an area largely cut off by roads.

"There are not any other woodlands close by for it to escape to," he said,.

Because the seeds of Cyrtosia are much larger than many other orchid varieties, which usually have seeds the size of dust that can easily be picked up by the wind, it may be harder for this orchid to take root elsewhere. Cyrtosia seeds need to be eaten and then spread, and also land on the perfect environmental conditions and fungi to survive.

If there is any chance that it could spread and displace any native plants, it will be destroyed, he said.

Of the tens of thousands of orchid varieties, many of which steal "oohs" and "ahhs" from visitors weaving their way through the gardens' warm, perfectly plucked greenhouses, the Cyrtosia septentrionalis would stand out — if it had ever been displayed there.

The deep red, tubular-looking fruit of a flower that has no leaves stood out on the outskirts of the gardens' experimental greenhouses this summer, catching the eye of David Sleasman, the gardens' director of library and information services, while he was on a lunchtime stroll in July.

"I grew up in the woods of Pennsylvania and never saw anything remotely similar," Sleasman said. "I noticed a flash of red in the shade several feet into the woods that drew me to walk toward it. That is an unusually bright color for that time of year — too early for leaves."

And because some orchids can go dormant for years or decades, that may be why it has been overlooked for so long.

Sleasman found the orchid in fruit, not flower, when it would look more like a peach-colored orchid with yellowish features. No one has yet seen Longwood's Cyrtosia at that stage, Zale said.

This orchid species is what experts call a "mycoheterotrophic orchid," a small subset of orchids that obtain their food from fungi. Some rely partially on fungi in varying stages of development; the Cyrtosia orchid has no leaves because it gets all of its nutritional needs from fungi, Zale said.

"It's critical to its life," he said. "That's part of what makes this find so remarkable. Not only that the seeds came here, but that it also found the fungus it needs. It's a really unique and specialized relationship, which is why it has been impossible for people to cultivate."

Now that it has been discovered thriving in the wild, the horticultural detective work can begin.

Based on Longwood's ordering records, Zale said it's possible the plant arrived in the late 1970s or early 1980s, hitchhiking on other plants coming from Japan.

Under the absolute perfect conditions, it is possible that tag-along seed was washed out of the research greenhouses and met the perfect kind of fungi to survive, the beginning of a decades-long secret relationship in the woods.

But for now, it's still a mystery.

"We want to understand what's going on back there," Zale said. "We're trying to figure it out. ... There's more information yet to come."

Contact reporter Maddy Lauria at (302) 345-0608, mlauria@delawareonline.com or on Twitter @MaddyinMilford.

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