Photospheric micro-turbulence of the sample non-radial pulsators (separated by the type of oscillations), and of the classical Cepheids and red giants and supergiants (symbols highlighted in light and dark blue, respectively) as a function of log g (left) and T_eff (right). For the case of non-RPs analogous results for non-pulsating stars of similar T_eff, log g and ℒ/ℒ_⊙ (colour-coded as indicated in Fig. 3), are also provided for a direct comparison. In each panel the horizontal dashed lines indicate the upper and lower limits to v_mic In the left fifth raw panel, the light and dark blue lines represent the mean v_mic, averaged within the subgroups of low- and high-mass Cepheids, respectively; in the bottom left panel, the red line indicates the least square fit to v_mic of the sample RGs thereby highlighting the deviation of RSGs from this trend. For more information see Appendix A.