Arizona Snow - it drifts, it floats, makes snow snakes in the street, can be tracked inside, collects on your clothes and hair, it whitens the yard, fluffs through the doorway, hides behind the pedestal sink in the hall bath....
It's the seeds from the Desert Broom.
The Desert Broom is more formally known as "Baccharis sarothroides".
It's a weed to many of us in Arizona.
I rather like the fluff. As noted, it's generally the closest we get to snow in Arizona.
As a plant...it's squirrelly.
It is a serious pain to eradicate and it seems to have a respectable sense of self-preservation - it excels at growing out of patches of Prickly Pear Cactus...where you can NEVER get to the root to pull it out. (This gent has taken some lovely pictures of Prickly Pear Cactus.)
And the fluff can stop up a pool filter pretty quickly.
However, I saw this lovely drift of Desert Broom seeds and Bouganvilla petals/leaves and I had to show you: