Milkweeds

One of the most common and well-known signs of fall is the milkweed seed pod. At this time of year it is possible to observe a variety of seed dispersal techniques plants have evolved in response to their habitat. Some seeds are enclosed within fruits (apples, berries) and spread by animals. Other plants, such as burdock, have seeds which easily clasp onto the fur of a passing animal and drop off later. Witch hazel has explosive seed pods; as the pod dries out the seeds are squeezed and eventually shoot out, away from the mother plant.

Many plants make use of wind and air currents to help distribute the next generation. Maple “helicopters” and milkweed “parachutes” are two examples. Seeds develop in a very orderly fashion within a milkweed seed pod. As September turns to October, the seed pods mature and dry, eventually splitting open. The seeds are released a few at a time; the hollow fibers of the “parachute” catch the air currents and may be carried many hundreds of feet away from the mother plant. Once the “parachute” catches in vegetation or lands in a sheltered site on the ground, the seed separates from the “parachute” and falls to the ground.

The fibers of the milkweed “parachute” were used to fill life jackets during World war II. The Natural Fibers Corporation in Nebraska is currently developing products from the fibers of the “parachute”, including pillows, and have found that the fibers have a higher thermal rating than goose down.

Milkweed seeds are eaten by small rodents like mice and voles and the “parachute” fibers may be found in bird nests next year. Look for the milkweed seed pods in open fields, along roads and in the small clearings on the Preserve. Enjoy your time on the mountain!

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