I don't have those libraries, I built my own L Systems a while ago just using Strings of characters. I would animate it by going through the String one character at a time in my draw loop and execute its rule.
I looked over your code and it seems like your L System is made up of "A", "B", "C", or "D". Have a global array that stores these instructions to run through later. Your code includes a lot of terms I have never used (notably branch) so it is hard for me to say where to add this.
sorry my mistake. branch is the name of the class, and the arms are the class instance's. there are multiple strings(types) running at he same time. I can take c and d out. i was just playing and added more.