  We consider a Hartmann layer, stationary flow of a viscose and resistive
fluid between two plates with superimposed transverse magnetic field, in the
limit of gyrotropic plasma, when viscosity across the field is strongly
suppressed. For zero cross-field viscosity, the problem is not well posed,
since viscosity then vanishes on the boundaries and in the middle of the layer,
where there is no longitudinal field. An additional arbitrarily small isotropic
viscosity allows one to find magnetic field and velocity profiles which are
independent of this viscosity floor and different from flows with isotropic
viscosity. Velocity sharply rises in a thin boundary layer, which thickness
depends both on the Hartmann number and on the Lundquist number of the flow.
  The implication of the work is that, in simulating ICM dynamics it is
imperative to use numerical schemes which take into account anisotropic
viscosity. Although magnetic fields are dynamically subdominant in the ICM they
do determine its the dissipative properties, stability of embedded structures
and the transition to turbulence.
