Ukrainian Snow and a Question

I know I've posted about this before, but in the spring, there are times it looks like it has snowed because of all the cottonwood trees that are here! The other day, the boys and I happened out to the playground and there was "poox" everywhere. Katya recently asked me what I call "poox" in English and I had no answer for her. Then she said, well what do you tell Canaan it is when you talk to you in English? I told her I used the Russian word! The Russian word is actually the word for down or fluff. So, my question to you is: does anyone know what we call all that white stuff that flies around in the air when there are cottonwoods or poplars around? If you do, let me know.
Anyway, I had Dougle bring the camera over to take pictures. At one point, the wind swirled all of it around the play ground and in the air and Canaan exclaimed, "It is SNOWING!" Well, not quite, but close.
Hope you enjoy the pictures of the boys and the "poox."

The first pic is not a good one, but the best I could get showing the snow swirling in the air. You can kind of see it on the trees. There is another pic below of Canaan showing of one of his excercises he is learning at gymnastics. (It is the one of him holding onto the bars and pulling his feet up- not very straight, but what he can do!) Also one of Canaan checking out the ground, because he is getting more interested in bugs these days. THe one of the boys in front of a story picture is at the playground too. They often draw little story pictures on walls near where kids play. And if you see Max's big bruises on his forehead and his cheek, he is getting them all the time these days. He is a bit of a daredevil and a bit of a clutz too. Just a growing baby boy!