User blog comment:Wythagoras/Extension of SCG/@comment-1605058-20130813135100/@comment-1605058-20130814201826

Even if that's right, how does it relate to CSCG(0,4)? If you use G8 same as we did, then trees can have only one valence 4 vertex, and at most 4 valence 3 vertices (any configuration of 5 gives G8 minor)