Simulated pollination of a pink lady's slipper orchid (Cypripedium acaule) by a bumblebee.
Simulated pollination of a pink lady's slipper orchid (Cypripedium acaule) by a bumblebee (Bombus sp.). There is a patch of about 15 of these plants near my home. Although each flower is open for a long time (three weeks or so), in the three years that I have been observing this patch, I have seen only one flower produce a pod. That means that for two of those seasons, I could conceivably have camped out next to these flowers for more than 12 hours a day, every day, for three weeks and not witnessed a single successful pollination event. So yes, I faked it. If you want to hire me to try to photograph the real thing, we can talk, but it ain't gonna be cheap. One reason pollination is so rare in this species is that the flower offers no nectar reward. It's not even clear whether the flower produces a pheromone-mimicking scent to attract bees. If not, the flower simply relies on shape and color to attract a curious bee, which squeezes its way into the opening at the front of the lower petal (see image D40641). Once inside, the bee is unable to leave the way it came, so it is forced to exit through an opening at the top of the flower (as seen in this photo), where it picks up a packet of pollen (a pollinium). To complete the pollination, the bee needs to make the same mistake a second time, with another flower, this time depositing the pollinium on its way out. Bumblebees are actually very good learners--instinct will only get you so far when you have to deal with the many different challenges flowers present to their pollinators. This suggests to me that the orchids may produce some sort of scent to attract bees and make them (occasionally) risk a second visit, but as far as I can tell, no one has investigated this hypothesis.
Size: 3456px × 5184px
Location: Haydenville, Massachusetts, , United States, USA
Photo credit: © Custom Life Science Images / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: acaule, bee, bumblebee, coevolution, cypripedium, islc, ladies, lady, ladyslipper, orchid, pink, pollination, slipper
