I am talking about rendering a tree without the tree itself. Da Vinci believed that you needed to be in nature to depict nature, I agree with Da Vinci. However, skilled artists can manipulate nature to serve certain functions. But to answer the posed question: you can't create something visually more stimulating than the natural world.
Walking outside and experiencing nature, I tend to get ideas about depicting a more interesting leaf, but still a leaf that exists in the world. I've been reading a lot lately about the animator, Hayao Miyazaki, who believes that depictions in his medium of animation need to be enhanced versions of the real world. All this leads to ideals that are a standard among the artists whom I admire. In fact, I would say without idealizing nature, there would be no poetic quality to a drawing. The natural world has its own ideal harmony as well. The leaves on the tree have an order that tend to cross my eyes with complexity, but as I draw, I fall into a rhythm of idealism where I try and capture the spirit of the limb or shrub.
I sat outside today and let my hand find the curves and the texture of the leaves. And I found deep happiness as I realized that I can never truly capture the air of the trees, birds, sounds and everything around me.