  We construct the effective field theory appropriate for describing the low
energy behavior of anisotropic Wilson lattice actions and the O(a) improved
variant thereof. We then apply this effective field theory to the hadron
spectrum and dispersion relations, focussing on the corrections due to the
anisotropy. We point out an important feature of anisotropic lattices regarding
the Aoki-regime; for a given set of fermion masses and spatial lattice spacing,
if an isotropic action is in the QCD-phase, this does not guarantee that the
anisotropic action is outside the Aoki-regime. This may be important in the
tuning of bare parameters for anisotropic lattices using domain-wall and
overlap fermions as well as Wilson and O(a)-improved Wilson fermions.
