Field of Science

Seed dispersal display

Fruits are flowers at the stage of seed dispersal.  As such many have attractive displays for the purpose of attracting seed dispersers with the promise of a reward, either the edible fruit itself or a fleshy seed coat, or a fleshy tissue surrounding the seed, an aril.  Here's the seed dispersal display of a sweet bay magnolia (Magnolia virginiana).  Magnolias have many pistils in each flower and each makes a fruitlet, usually a tough little dry follicle that opens along one seam to release or reveal one or two aril-covered seed.  The bright orange-red fleshy aril is both the visual attraction and the reward, the seed has a dark-brown tough seed coat. The seeds actually dangle on a thread to attract even more attention from birds who after digesting off the aril regurgitate the seed.  Displays like this can last days, and disappear quickly when a flock of cedar waxwings stop by.

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