Spectroscopic Hertzsprung-Russell diagrams (Langer & Kudritzki 2014, /g) for non-rotating, rotating at υ/υ_crit = 0.2, and rotating at υ/υ_crit = 0.4 with moderate and strong transport. The black solid lines connecting the red hooks of the tracks show the TAMS position for alpha = 0.3, the dashed lines show the TAMS line for overshoot parameters equal to 0.1, 0.2, 0.4, 0.5, and 0.6. The dashed-dotted red lines show respectively the empirical ZAMS (on the left in each panel) and the empirical TAMS limit (on the right in each panel) given by Castro et al. (2014). The shaded areas show the kernel density estimation of stars from Castro et al. (2014) sample. It uses a Gaussian kernel, and the darker is the area, the higher is the proportion of the estimated underlying distribution that sits in that range.