And a host of others too since one of the many is Diebenkorn, but what is the problem to be addressed? The tree is not the problem: the tree is the armature upon which to build the painting and I think this holds true for me when, for example, I make a self-portrait and my face serves as the hook upon which I hang the paint. Sometimes it looks the way I look: sometimes the paint becomes a tree.
Colour sometimes works to confound recessional space so when I look at part of the tree (the trunk) and the space surrounding it,painting that can result in three flat sections, each with its own presence. This morning the trunk was a grey blue red but this afternoon it may be a pale green.