but there are different levels of membership. For example, most stumps rot away into humus and disappear within a couple of hundred years (which is not very long for a tree). Only a few individuals are kept alive over the centuries, like the mossy “stones” I’ve just described. What’s the difference? Do tree societies have second-class citizens just like human societies? It seems they do, though the idea of “class” doesn’t quite fit. It is rather the degree of connection—or maybe even affection—that decides how helpful a tree’s colleagues will be