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Angiosperm Phylogeny Group

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The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships discovered through phylogenetic studies.   

Image of Angiosperm Phylogeny Group (APG)Opens in a new windowen.wikipedia.org

The APG has published four classification systems since 1998, with the latest being APG IV in 2016. These systems are based on molecular phylogenetic studies, which have revealed many new insights into the evolutionary relationships among angiosperms.

The APG systems have had a major impact on the classification of angiosperms, and they are now widely used by botanists and other scientists. They have helped to clarify the relationships among angiosperm families and orders, and they have also helped to identify new groups of plants.

The APG systems are not perfect, and they are still being refined as new information becomes available. However, they are the most comprehensive and up-to-date classification systems for angiosperms available today.

The Angiosperm Phylogeny Group III (APG III) system is a significant milestone in the classification of flowering plants. It represents a comprehensive and updated framework based on the latest molecular phylogenetic research. This system aims to reflect the evolutionary relationships among different plant groups more accurately than previous classifications.

Key Features of APG III:

  • Molecular Phylogeny: The system relies heavily on DNA sequence data to infer evolutionary relationships.
  • Cladistic Approach: It employs a cladistic approach, grouping organisms based on shared derived characteristics.
  • Monophyletic Groups: The system strives to recognize only monophyletic groups, meaning that all members of a group share a common ancestor.
  • Reduced Emphasis on Morphological Features: While morphology is still considered, the focus is increasingly on molecular data.

Major Changes Introduced by APG III:

  • Reorganization of Major Groups: Some traditional groups were reorganized or redefined.
  • Recognition of New Families: Several new families were recognized, reflecting the increased resolution of molecular data.
  • Changes in Family Delimitations: The boundaries of some families were adjusted based on new phylogenetic insights.
  • Increased Emphasis on Subfamilies: Subfamilies were given more prominence in the classification.

Significance of APG III:

  • Improved Understanding of Plant Evolution: APG III provides a more accurate picture of how different plant groups are related to each other.
  • Enhanced Communication Among Botanists: A standardized classification system facilitates communication and collaboration among researchers.
  • Practical Applications: The system has practical implications for plant identification, conservation, and agriculture.

While APG III was a significant advancement, it has since been superseded by the APG IV system, which incorporates further refinements and updates. However, understanding the principles and key changes introduced by APG III remains essential for comprehending the current classification of flowering plants.

Would you like to learn more about specific changes or groups within the APG III system?

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