  Compression dramatically changes the transport and localization properties of
graphene. This is intimately related to the change of symmetry of the Dirac
cone when the particle hopping is different along different directions of the
lattice. In particular, for a critical compression, a semi-Dirac cone is formed
with massless and massive dispersions along perpendicular directions. Here we
show direct evidence of the highly anisotropic transport of polaritons in a
honeycomb lattice of coupled micropillars implementing a semi-Dirac cone. If we
optically induce a vacancy-like defect in the lattice, we observe an
anisotropically localized polariton distribution in a single sublattice, a
consequence of the semi-Dirac dispersion. Our work opens up new horizons for
the study of transport and localization in lattices with chiral symmetry and
exotic Dirac dispersions.
