APGien

APGien is a term that refers to the classification system of plants developed by the Angiosperm Phylogeny Group (APG). The APG is an international group of systematic botanists who collaborate to establish a comprehensive and widely accepted system for the classification of flowering plants, or angiosperms. The APG classification system is based on phylogenetic principles, which means it reflects the evolutionary relationships among plants.

The first version of the APG classification system, known as the APG system, was published in 1998. It was a significant departure from traditional systems, such as the Cronquist system, as it incorporated extensive molecular phylogenetic data. This approach provided a more accurate representation of the evolutionary history of angiosperms. The APG system was subsequently updated in 2003 (APG II), 2009 (APG III), and 2016 (APG IV), each time incorporating new data and refining the relationships among plant groups.

The APG classification system organizes angiosperms into a hierarchy of clades, which are groups of organisms that include an ancestor and all its descendants. The highest-level clades in the APG system are the magnoliids, monocots, eudicots, and a few smaller groups. These clades are further divided into orders and families, with the families being the most commonly used taxonomic rank in the APG system.

The APG classification system has been widely adopted by botanists and is used in many textbooks and reference works. It has also been incorporated into databases and online resources, making it a valuable tool for researchers and students alike. The ongoing updates to the APG system ensure that it remains a current and accurate representation of the evolutionary relationships among flowering plants.