Self setters

I love finding plants or even trees that shouldn't be there - the ones blown in on the wind or seeds carried along by man, train or vehicle. I have no idea where this poppy came from. I was reminded of its existence by a similar posting by Two Terriers and here is my example. Growing out of a crack in the wall - aren't the best self setters growing out of wall cracks? Any cracks for that matter, as that is where the seed usually rests.