The "Add a Branch" button is necesary for you to see anything except for the preset fractals like Parsley and L system. First add a branch to get started, then adjust the detail of the fractal. WARNING: the amount of detail coupled with the number of branches is a deadly combo and will destroy your computer unless you have legendary RAM (the "Size " is also a contributor to this). The same goes for too many branchs of the L system. Another feature is that the "Benice" button can be added upon all iterations of the traditional fractal tree but not the Parsley Tree or the L system tree.