What Sets the Orchid Apart from Other Flowers?

Cymbidium Half Moon ‘Wonderland’

A turnip flower

“What makes this plant an orchid and not a turnip?” asks Steve Robinson, enticing visitors like me to stop and chat with him at an exhibit of Latin American orchids. Robinson, a docent at the Smithsonian National Museum of Natural History, carefully shows me the back of an orchid flower, indicating the colorful sepals. “Only an orchid has three sepals that resemble petals, two true petals and one labellum, or lip.” The structurally complex and wildly colored flowers of orchid-family plants have intrigued botanists, collectors and breeders for hundreds of years.

A turnip, in contrast, bears simple cross-shaped flowers with four equally sized petals. Turn the flower over and you’ll see four plain green sepals. Kind of ho-hum in the flower world.

Psychopsis ‘Mariposa Mountain’

If you’re lucky enough to visit Washington, D.C., during cherry blossom season, the “Orchids of Latin America” exhibit is worth a visit. Not only is it a feast for the eyes, it also reveals the role that orchids play in the biodiversity of their native habitats, from Mexico to Chile. The show continues through April 21.

Here are photos of just a few of the incredible orchids I saw. To learn more about the exhibit, visit Orchids of Latin America. Oh, and if Steve Robinson poses the orchid/turnip question, now you can answer him: It’s all about the unique shapes of the flowers.