All plainly visible after snow as at no other time: a bit of lichen fallen from a branch,
some bark fragments, and a lot of tiny particles of what might be soil or dust. (2/7/15)
I have been accumulating seeds for the native trees I plan to plant in spring; all except one: I had no paper birch seeds. The few local trees I know of carry their branches too high for me to reach, but waiting to collect the seeds from the ground isn't practical, because they are so small and hard to see. Mindful of the snow trick, I headed straight for the paper birch down the street today. Even though the snow was days old and partly melted, I quickly spotted a few tan samaras. They were very thinly scattered, so it took probably five minutes to collect a small pinch to bring home and try to sprout. Passersby on the busy main road saw an old guy bent over, carefully picking up invisible objects--adding to the Lore of the Crazy Neighbor. But, then, I'm used to it.
Birch samaras are tiny things--no more than two or three millimeters wide.
The two little wings help ensure that the young are dispersed so as not to
grow up in the shade of their mother. Bottom right in the second photo,
looking a bit like a fleur de lis, is a scale from a "cone" of the same tree.
I cannot help thinking of the sausage-shaped fruits of birch as anything but "cones,"
since they are built a bit like pine cones.