I work for a program where we have campfire everyday. The staff sings this song after the kids leave, everyday. We sing a lot of these versions you have listed. We also have one of our own.
Trees, trees, trees, trees
When I sleep I dream of trees
Alder, Maple, Yew and Hemlock
See how they grow
Some folks also sing the following song to complement the round.
Building bridges between our divisions
If I reach out to you will you reach out to me
With all of our voices and all of our visions
Friends we can make such sweet harmony
Hope that helps.