In the context of the phylogenetic classification of angiosperms, we remember the significant change that the new system of APG 2009 III represented, according to the Latin numbers, and 11 years after the first APG system was published in 1998. It was the third version of a modern plant taxonomy system, based mainly on molecular studies, for flowering plants (angiosperms), which was developing as the Angiosperm Phylogeny Group III (APG III). In 2009, a linear arrangement of the system was separately published. APG III ordered and grouped angiosperms into 415 families and 59 orders. These orders, in turn, were distributed into clades. The latest APG IV system for the classification of flowering plants was published in 2016, seven years after its predecessor, which was published in 2009. Compared to the APG III system, the APG IV system recognizes five new orders (Boraginales, Dilleniales, Icacinales, Metteniusales, and Vahliales), along with some new families, making a total of 64 orders of angiosperms and 416 families. Generally, the authors describe their philosophy as "conservative," based on making changes from APG III only where a "well-supported need" has been demonstrated. This has sometimes resulted in placements that are not consistent with published studies, but where further research is needed before the classification can be changed.