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#angiosperm classification

2 public questions tagged with this topic.

Plant Classification

ANA grade includes

ANA stands for Amborellales monotypic Amborella trichopoda endemic New Caledonia, Nymphaeales including Hydatellaceae, Cabombaceae brasenia Cabomba and Nymphaeaceae water lilies, Austrobaileyales comprising Austrobaileyaceae, Schisandraceae e.g., Illicium star anise and Schisandra, Trimeniaceae. Together they form grade of three successive divergences preceding mesangiosperms, not monophyletic clade but paraphyletic assemblage, about 300 species total. Alternative options list magnoliid orders Piperales Laurales Magnoliales Canellales, or monocot families Poaceae Orchidaceae Asparagales, or eudicot clades. Grasping ANA composition essential for understanding ancestral flower reconstruction and evolutionary innovations like carpel closure evolution.

Ref: Campbell Biology, 12th ed., Chapter 30: ANA grade constituents Amborella Nymphaeales Austrobaileyales

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Plant Classification

According to APG IV classification, angiosperms are classified mainly based on

APG IV system published 2016 revises classification using comprehensive plastid rbcL atpB matK ndhF and nuclear 18S gene matrices analyzed via maximum likelihood Bayesian inference, abandoning sole morphological reliance because floral characters highly homoplasious due to pollinator adaptation and convergence. Synapomorphies defined by molecular substitutions support monophyletic orders and families worldwide. Data sources include whole plastome sequencing, transcriptomics, revealing that Amborellales diverges first then Nymphaeales. Fossil record calibrates divergence times but not basis of group circumscription. Thus DNA sequence data provides primary criterion for family delimitation, improving stability compared to Cronquist morphology-based system previously dominant and artificial.

Ref: APG IV 2016, Botanical Journal Linnean Society 181:1-20, DNA sequence classification basis

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