Seed in 'plastic'

I was working in the vegetable beds the other day and started picking out little rocks and other debris that the rains had brought to the surface. I spotted this, thinking it was a piece of plastic, and picked it up. Even up close, it looks as if this seed is wrapped in cellophane wrap, but those are its natural wings.

The seed itself is similar in size to a small rolled oat flake. I don't know what kind of seed it is but I found some seed identification sites to bookmark for future reference:

SCRI Seed Identification - by description

Ohio State Seed ID workshop - by scientific name