Flowers Fool Flat-footed Flies by Faking Fungus-infected Foliage

A rare species of lady’s slipper orchid (Cypripedium fargesii) grows black spots that look like a fungus. But it’s not a fungus; it’s a feature, as Zong-Xin Ren of the Chinese Academy of Sciences found out during four years of research.

The lady’s slippers are generally pollinated by bees but C.fargesii is different. Over many hours of observation, the only insects that Ren ever saw leaving the flowers were flat-footed flies. Ren captured four of them and when he peered at them under an electron microscope, he saw pollen grains from the orchid, and spores from a fungus called Cladosporium. This fungus infects leaves and fruits, and when it does so, it produces black mold spots. The purpose of the orchid’s black splotches was becoming clear.
Ren also analyzed the orchid’s scent, an unpleasant fragrance reminiscent of rotting leaves. He found that the flower produces over 50 aromatic molecules that are found in other flowers, but three unusual ones that are common to Cladosporium molds.

Like they always say, you catch more flies with fungus than with vinegar. Cypripedium fargesii is not the only orchid that attracts pollinating insects by deception, as you’ll see in the article at Not Exactly Rocket Science. The article also illustrates the importance of humorous headlines.

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