Temperatures from Newton et al. (2015) EW-based relation (circles) and Mann et al. (2013b) K-band relation (squares) vs. visually assigned spectral type (left) and automatically assigned ﹩{{\rm{H}}}_{2}{\rm{O}}﹩-K2 index-based spectral types (right). For reference, the black line shows the spectral types and temperatures reported by Boyajian et al. (2012) for interferometrically characterized stars. Note that Boyajian et al. (2012) report temperatures at half spectral types between M0 and M4. All points are color-coded by [Fe/H] as indicated by the colorbar.