Common Flax

I had no idea what this flower is, but once again Molllyblobs came to the rescue and told me that it's a common flax. I was pretty certain that it's grown from bird seed, as there's a big patch of these plants underneath our bird seed feeder, and Mollyblobs confirmed that common flax is often included in bird seed mixtures.

I love the paper-thin petals. There are white flowers too, but I think the blue ones are much prettier.