"Sidewalk Art"

As I was walking back from the doctor, I stopped to take this picture. When the cement of poured for the concrete sidewalk, a leaf got caught in it, resulting in this imprint or "fossil."
I'm working on a series of these and hope to publish them at some point. This one is a silver maple, I think.

It isn't really sidewalk "art," unless you call it "found art," and I would like another name for the series.