L-system Drawing

This Processing sketch features a truly l-system based plant. I haven't figured out how to "grow" this plant in the same way as the very curly other one. When you click in the window of this sketch it jumps another generation in the weed drawing formula.

Based on the l-system rule: (X → F-[[X]+X]+F[+FX]-X),(F → FF)
Example 8: Fractal plant from wikipedia