  We report measurements of the electronic structure and surface morphology of
exfoliated graphene on an insulating substrate using angle-resolved
photoemission and low energy electron diffraction. Our results show that
although exfoliated graphene is microscopically corrugated, the valence band
retains a massless fermionic dispersion, with a Fermi velocity of ~10^6 m/s. We
observe a close relationship between the morphology and electronic structure,
which suggests that controlling the interaction between graphene and the
supporting substrate is essential for graphene device applications.
