A small tree in my yard has leaves which appears to double over themselves. The first two pictures show this phenomena, and the third is the same tree to maybe aid identification.

[![enter image description here][1]][1]
[![enter image description here][2]][2]
[![enter image description here][3]][3]

I can't absolutely guarantee when this first appeared, but I believe it was this growing season, and I know it's been there at least a month (unless it's reoccurring, I am not tracking the individual leaves).

My first thought is cocoons or some other insect behavior. Can anyone tell me what it is?

(What kind of tree it is will also be valuable, in case we can't find the answer to the leaf question here)

  [1]: https://i.sstatic.net/voOII.jpg
  [2]: https://i.sstatic.net/A6r3D.jpg
  [3]: https://i.sstatic.net/q4gWW.jpg