Solid line: distribution of total stellar mass contained in galaxies with a given stellar mass. The points with error bars are the measurements of the SMF presented in van der Burg et al. (2013), but integrated over the mass bins. Dotted line: spectroscopic completeness for galaxies with projected distances from the BCG less than R₂₀₀. For the galaxies that constitute most of the stellar mass in the clusters, the spectroscopic completeness is high (≳50%).