weed recursion plant like l-system mathematical model

background pattern concept abstract vector self-similar rewrite self-similarity self-contacting binary recursion endless repeating iteration l-system lindenmayer system mathematical model mathematics curve graph curvature figure geometrical geometry geometric structure diagram branching branched truncated tree plant weed herb grass inflorescence panicle whisk wisp tree-like dendritic arborescent dendriform dendroid arboraceous dendritical root