The seeds of maple trees are shaped like single wings and rotate around the heavy seed end when tossed into the air. The twirling motion is unexpected because most leaf-like objects fall in a less regular fashion. Collect some for a rainy day. Have children spread out so no one bumps heads, then toss the seeds into the air. The children in one class leaped to catch then bent low to pick up the seeds, over and over again. The seeds will keep for a few weeks.
Maple Seed Helicopters by NASA has a lesson with plans for making additional rotating “seeds” from stiff paper, with information on the “why” of it. My grandfather showed us how to carefully split the seed casing, opening it to reveal the sticky cotyledons (first leaves and food for the sprouting seed). Then he put the sides on his nose so he looked like a rhinoceros! See a photo of how to do this on The BIG Fieldtrip, the Kirkman family blog, October 13th, 2009 entry, Bella’s Seeds (thanks, Kirkman family!). Some maple trees produce seeds in the fall and some in the spring so we get two chances a year to play with these seeds.
Peggy