  We have put forward a new unified framework which provides a consistent and
rather complete account of the growth index of matter perturbations in the
regime where the dark energy is allowed to have clustering. In particular, we
find that the growth index is not only affected by the cosmological parameters
but rather it depends on the choice of the considered dark energy (homogeneous
or clustered). Using the {\em Planck} priors and performing a standard
$\chi^2$-minimization between theoretical expectations and growth data, we
statistically quantify the ability of the growth index to represent the
observations. Finally, based on the growth index analysis we find that the
growth data favour the clustered dark energy scenario.
