For a knotted graph in S-3 we define the vertex constant group, a quot
ient of the fundamental group of the complement. For planar graphs the
group is cyclic. For graphs with periodic symmetry the group is relat
ed to the fundamental group of the branched cover of S-3 branched over
knots contained in the quotient of the graph under the symmetry. Thes
e tools are used to demonstrate that a large family of knotted graphs
are not planar.