Aim The global richness gradient of angiosperm families is correlated with current climate,
and it has been claimed that historical processes are not necessary to understand patterns
of plant family richness. This claim has drawn criticism, and there have been doubts about
the quality of the data used to quantify the pattern. We revisit this issue using the
Angiosperm Phylogeny Group (APG) III classification and revised range maps, and we
incorporate an evolutionary variable, family age, to explore covariation between evolution …