Blowing in the Wind

It looked as though it had been snowing this morning when I pulled up the blinds and saw the grass covered in white and what looked like snowflakes floating past the window on the breeze.
When I investigated I discovered it was like flimsy cotton wool, covering little oval green seed pods in various stages of bursting open.

This could be the work of a variety of the poplar tree, perhaps the Black Poplar, but if anyone else knows differently and wants to contradict this, I would be delighted.
It is certainly an ingenious way for the seeds to be transported by the light as air white fluff surrounding them.