From the Washington Post on orchids:
“The orchid’s game is seduction, and it works on people too,” says Tom Mirenda, one of the exhibit’s curators. “What better strategy on a changing planet than to become the pet of the most successful creature?”
Why are the flowers so beguiling to humans? The secret may lie in their bilateral symmetry — meaning there’s only one way to fold them in half so that one side matches the other. (Most other flowers have wheel-like radial symmetry, with many possible midlines.) This gives orchids a face-like appearance, or maybe something more suggestive.