A Leaf Can Be ... by Laura Purdie Salas, illustrated by Violeta Dabija is a soft, lovely exploration of all the different things a leaf can be. It's rhyming text floats along with the artwork that combines traditional and digital techniques. There is an author note that goes into more detail about each job that is described. There is also a glossary and further reading on leaves.
I'm not usually as excited about many digital techniques, but I like the ones used here. On the back jacket flap under the illustrator it defines the illustrations as delicate and atmospheric. That description is aptly put. I like the softness and ethereal feel of the art. It certainly takes on the naming the different functions of a leaf to greater heights.
I would use this story in a leaf or tree Storytime. It could be used for older ages than preschool, I would use this as a nice read-aloud to K - 2nd grade, and maybe even for 3rd & older if used with higher level nonfiction books. This picture book could be used as a 'relief' book, not as much information thrown at you, but you have to stop and think a little about what the author means, a good book to get you 'thinking'.