Answer to the Friday Whatsit for June 30, 2010
My Aunt Linda (who prefers to leave her guesses in comments on Facebook) guessed correctly when she said that it is grass seed. This is what happens if you let your grass get too long and it goes to seed. And then the Friday Whatsit is what happens when you pick some of it and take an image under a microscope.
So there you have it, grass seed from an unidentified variety of grass.