Rotation histograms for the cluster members that were searched for flares and had measured rotation periods P_rot. Rotation periods were taken from Douglas et al. (2019) for the Hyades (orange solid) and Praesepe (yellow dashed), and from Rebull et al. (2016) for the Pleiades (maroon dotted). The numbers and percentages in the legends in each panel denote the number of stars for which periods were given, and what fraction of the full sample that represented, respectively. The period distributions of Praesepe and the Hyades are consistent in all T_eff bins but the 3500−3750 K bin, where the distribution of the Hyades appears more similar to the younger Pleiades than the same-age Praesepe. However, the sample size for the Hyades in that bin is small (11 stars).