Partial Restoration of Flavor Symmetry for Chiral Staggered Fermions
  At non-zero lattice spacing the flavor symmetry of staggered fermions is broken to a discrete subgroup. We show that in the chiral limit the flavor symmetry of the pion effective Lagrangian enlarges to an SO(4) subgroup of the continuum SU(4) symmetry. This provides an explanation for observed degeneracies in the pion spectrum. 
Weonjong Lee and Stephen Sharpe