Today’s featured floral form is Caleana major, an orchid from Australia. It looks like a duck. It flies like a duck when the wind blows, but it’s just a flower. Why would an orchid develop such an elaborate costume? The answer is again pollination.
While this may look like yet another case of autotroph posing as heterotroph, it’s not the one you think. Caleana major’s flowers are designed to attract male sawflies. When the flies enter the larger ‘body’ portion of the flower, the ‘neck and head’ portion of the flower snaps closed behind them. For about a minute or so, the sawflies buzz around in a slight frenzy and become coated in pollen. This ensures that flower pollinates itself and any pollen remaining on the fly travels with it to the next flower.
The secret to this strategy is the sensitive ‘neck’ strap of the flower. This portion can sense when a fly has landed within the bottom part of the flower and trigger a response to have the ‘head’ snap closed. This trigger must also be reversed on a relatively short timescale to release the captive fly. He just needs enough time to be coated in pollen but none the worse for wear (unlike other carnivorous plants that intend on killing their insect victims with triggered mechanical responses).
There must be some interesting biochemistry underneath that response, not to mention the developmental gymnastics that must occur to make flowers that look like flying ducks. I’m not sure scientists will figure out these tricks because Caleana major cannot be cultivated outside its native environment. Because of its novel form and potential popularity with orchid enthusiasts, experienced growers have tried to grow it under greenhouse conditions, but with little success. It is speculated that a symbiosis with another microorganism in the soil of its native habitat is necessary for growth.
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