Fig. 1.

Species richness and diversification rates in 310 botanical countries. (A) Species richness (SR) is the number of species in a botanical country. (B) Diversification rates are estimated as mean root distance (MRD), which is the average number of edges from tip to root in a phylogeny of all species occurring in a botanical country. A, Right and B, Right show scatterplots of the map data with local polynomial regression (gray lines) and 95% CIs (light gray areas) of SR and MRD to highlight latitudinal patterns. Botanical countries with areas smaller than 1,200 km² (n = 12) are highlighted with thicker border lines. Maps are in Behrmann equal-area projection.