How does the APG classification system differ from the older Cronquist system for Magnoliales?

The classification of the order Magnoliales has evolved significantly between the older Cronquist system and the modern Angiosperm Phylogeny Group (APG) system.12

The primary differences include:

• Methodological Basis: The Cronquist system (1981) relied on similarities and differences in morphological, anatomical, and chemical characteristics. In contrast, the APG system is based on phylogenetic data derived from molecular techniques, specifically DNA sequencing, which provides more robust and testable evolutionary relationships.23
• Hierarchical Structure: Cronquist organized flowering plants into two classes—Magnoliopsida (dicots) and Liliopsida (monocots)—with multiple subclasses. The APG system avoids formal taxonomic ranks above the level of order, preferring a less hierarchical arrangement.23
• Placement of Magnoliales: Under the Cronquist system, Magnoliales was placed within the subclass Magnoliidae. The APG system reclassified these plants into the magnoliid clade, an informal grouping of basal angiosperms that includes the orders Magnoliales, Canellales, Laurales, and Piperales.13