Overall, the changes from APG III (2009) to APG IV are minimal. Stability is an important aspect of our approach to this classification, and the APG system has remained remarkably consistent since its incep- tion. Little remains now that requires attention, although reorganizations and changes of familial cir- cumscriptions will continue, particularly in Caryophyl- lales, Lamiales and Santalales, for which more data are needed to provide a robust picture of generic and familial relationships. The advent of routine whole- plastid genome sequencing and nuclear gene sequenc- ing should remedy this situation, as it has done for the early-diverging lamiids. Of course, new phylogenetic understanding may necessitate description of new fam- ilies, as were the cases with Kewaceae, Macarthuri- aceae, Microteaceae and Petenaeaceae, but this appears to be the most likely source of new data that will require future alteration of the APG system.