  This work is focused in the stability and magnetic properties of complex
graphene multivacancy systems, studied by Density Functional Theory
calculations. The removal of a sequence of carbon atoms -i.e. the complementary
figure- leads to these multivacancy systems. We show evidence that
dendritic-like complementary figures yield to very stable defected graphene
structures. If this dendritic complementary figure is aliphatic, the stress of
the defected graphene system is enough to decrease the symmetry of such a
system. In the cases that the complementary figure is based in phenyl- or
pyrenyl-like cores, the remaining system with the vacancy will preserve the
symmetry of the removed segment yielding to flower-like structures after
optimization. This has consequences in the magnetic arrangement based on the
dangling bonds located at the loose vertices of the pentagonal rings. The cases
with orthogonal anisotropy, the magnetic order is driven by the symmetry of the
vacancy system -i.e. the symmetry of the complementary figure-.
