  A field theoretic representation of the classical partition function is
derived for a system composed of a mixture of anisotropic and isotropic mobile
charges that interact {\sl via} long range Coulomb and short range nematic
interactions. The field theory is then solved on a saddle-point approximation
level, leading to a coupled system of Poisson-Boltzmann and Maier-Saupe
equations. Explicit solutions are finally obtained for a rod-like
counterion-only system in proximity of a charged planar wall, generalizing the
standard Gouy-Chapman results. The nematic order parameter profile, the
counterion density profile and the electrostatic potential profile are
interpreted within the framework of a nematic wetting layer with a (Donnan)
potential difference.
