Autumn seed dispensers - beautifully functional natural architecture

 Seeds' pods and capsules are remarkable examples of beautiful, functional natural architecture. The two photographs below show what happens when seed pods of American willowherb Epilobium ciliatum are ripe. The pod splits longitudinally into four sections that gradually curl backways, dragging with them the hairy 'parachute' plumes of the rows of seeds, which eventually break free and are carried away on the wind. 

Mouse-ear chickweed carries its seeds inside a translucent, flask-shaped capsule which has a ring of teeth around the opening. The teeth respond to changes in surrounding moisture, opening to release seeds when they dry out.

Cowslip seed capsules (below) also open via a ring of teeth that curl backwards in dry air. These capsules are still full of seeds which, after shedding, will usually remain dormant in the soil until spring, needing the low temperatures of winter to break their dormancy.

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.