Monday, July 6, 2009

An Exquisite Seed Dispenser


This elegant little object is the glassy seed capsule of a common and easily overlooked wild flower: mouse-ear chickweed Cerastium fontanum. You can find an excellent photograph of the plant in bloom over at http://northumberlandnaturalist.blogspot.com/2009/07/cottonshope-burn.html
After the flowers fade they're followed by these exquisitely formed seed containers, each about a centimetre long at maturity. This capsule has shed all of its seeds except one, which you can just make out inside the vase-shaped neck. Those teeth that surround the opening bend back to allow the seeds to be shaken out in dry weather and close up when it’s wet – a mechanism that also operates in white campion seed capsules. You can make it go through the motions by putting it in a sealed container with moist paper towel in the bottom, then bringing it out into dry air.

2 comments:

  1. Fascinating Phil, and so clever to open like that at the right time. I find that incredible how that has evolved how to do that.

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  2. Hi Keith, it's the same mechanism that opens and closes pine cones - microscopic fibres in the dry cell walls that expand or shrink when the absorb water of dry out, that bend the whole structure.

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