  We present numerical radiation-hydrodynamic simulations of the evolution of
HII regions formed in an inhomogeneous medium resulting from turbulence
simulations. We find that the filamentary structure of the underlying density
distribution produces a highly irregular shape for the ionized region, in which
the ionization front escapes to large distances in some directions within
80,000 years. In other directions, on the other hand, neutral gas in the form
of dense globules persists within 1 parsec of the central star for the full
duration of our simulation (400,000 years). Divergent photoablation flows from
these globules maintain a root-mean-squared velocity in the ionized gas that is
close to the ionized sound speed. Simulated images in optical emission lines
show morphologies that are in strikingly detailed agreement with those observed
in real HII regions.
