was published in 2009, and 18 years after the first APG system was published in 1998. In 2009, a linear arrangement of the system was published separately; the APG IV paper includes such an arrangement, cross-referenced to the 2009 one.

Compared to the APG III system, the APG IV system recognizes five new orders (Boraginales, Dilleniales, Icacinales, Metteniusales