Wednesday, June 6, 2012

Pink Lady’s-slipper

Of all the native orchids in the Northeast, I've encountered the Pink Lady’s-slipper or Moccasin Flower (Cypripedium acaule) more often than other species.  In addition to bog edges, it can survive in drier pine woods. Acidic soil seems to be the common denominator.

The bottom petal, inflated into a hollow pouch, is longitudinally cleft almost the entire length, providing access to larger insects like bumblebees in search of nectar, although smaller bees in the family Andrenidae are the major pollinators.  Charles Darwin observed that once inside, the smooth, “slippery” pouch interior and incurved edges of the main opening force the bees to leave by a smaller opening where they first brush against the (female) stigma which dislodges any pollen and then the bees pass the (male) anthers where they pick up new pollen that could be carried to the next lady’s-slipper.  After successful pollination the blossoms quickly discard their beauty as the top (dorsal) sepal drops down to seal the opening.

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1 comment:

  1. I was not familiar with this plant, thanks for the informative article! Pollination is fascinating!