Yesterday I escaped the city to explore the orchid-rich tropics—just a half-an-hour outside D.C.
I took a behind-the-scenes tour of the recently opened Smithsonian Gardens greenhouses in Suitland, Maryland, which house a collection of about 8,000 orchids used in education, exhibitions, and scientific research. (See orchid pictures.)
Tom Mirenda, a Smithsonian orchid expert, first told our group a bit about orchids. For instance, most of the plants—found everywhere but Antarctica—are epiphytes, which means they grow on other plants, usually trees. (Wild orchids usually hang upside down—the flowers you might have seen in gardens or people’s homes are actually staked upright.)
As we walked along the many aisles of plants, a light mist falling from above, Mirenda stopped to point out a few highlights, such as the pretty chocolate orchid, which had a sweet (but maybe not quite chocolatey) smell. I was surprised how different plants looked—some of them didn’t look like your, well, garden-variety orchid at all.
That’s because “that the way a flower looks has everything to do with its ecology”—ie. the flower evolved to suit its pollinator, Mirenda told us.
Take, for instance, the spider orchid, whose spiky leaves resemble a spider to attract spider-eating, parasitic wasps, which then end up pollinating the orchid.
“They can’t help themselves—they’re looking for spiders to lay their eggs,” he said. Many orchids feature a “landing pad” and “handlebars” that allow an insect easier access to its pollen.
(Learn more about orchids in National Geographic magazine.)
Then there’s the mysterious butterfly orchids in the Psychopsis genus. No one knows how they’re pollinated, though it’s likely has one or two clever tricks: The butterfly-like flower might attract a parasitic insect on the lookout for butterflies, or it fools a male butterfly into thinking it’s a female.
There’s even a fun word for it: pseudocopulation. Either way, the orchid succeeds in getting its seeds distributed to continue the life cycle. We got to see a hybrid butterfly orchid, Psychopsis mariposa, below.
Another oddity is the ghost orchid, Dendrophylax fawcetti, so named because it lacks leaves—it photosynthesizes through its roots—and because sometimes it has a pale white flower that “pops out of nowhere,” Mirenda said.
The bucket orchid has also evolved a creative strategy: Its pollinator, a type of tropical bee, falls into the flower’s lip, which is full of a liquid secreted by the flower.
“But he doesn’t die—instead, the frantic bee is funneled to an escape hatch where pollen is surreptitiously deposited on his back and then freed. The pollen-laden bee is happy because on his visit, he was able to collect a fragrance attractive to female bees, despite its harrowing, near-death experience,” Mirenda said.
Our last visit was a sweet surprise: A sprawling vanilla orchid, which was taller than a man and stretched over our heads. Their seed pods yields vanilla extract, and according to Mirenda, vanilla orchids can grow as quickly as philodendron.
But most orchids aren’t doing so well. About 65 percent of North America’s 208 orchid species are in trouble, mostly because they’re so closely tied to their environments—for instance, orchids rely on certain fungi to survive.
Until recently, there was no major enterprise to save North American orchids. But that’s changed with the newly launched North American Orchid Conservation Center, a national public-private partnership that includes the Smithsonian and the U.S. Botanical Garden, said Dennis Whigham, of the Smithsonian Environmental Research Center.
Among its goals, Whigham told us, is creating repositories for orchid seeds and the fungi which with they live. The conservation center will also work with regional botanic gardens and private landowners to conserve orchids.