Pentapetalae

In phylogenetic nomenclature, the Pentapetalae are a large group of eudicots that were informally referred to as the "core eudicots" in some papers on angiosperm phylogenetics. They comprise an extremely large and diverse group accounting for about 65% of the species richness of the angiosperms, with wide variability in habit, morphology, chemistry, geographic distribution, and other attributes. Classical systematics, based solely on morphological information, was not able to recognize this group. In fact, the circumscription of the Pentapetalae as a clade is based on strong evidence obtained from DNA molecular analysis data. The Pentapetalae clade is composed of the orders Berberidopsidales—including the family Aextoxicaceae—Caryophyllales, Santalales and Saxifragales, the families Dilleniaceae and Vitaceae and all members of the clades Asteridae and Rosidae. Phylogenetic analyses of complete chloroplast genome sequences have provided a reliable outline of the relationships among the major Pentapetalae lineages and also provide a framework for investigating the evolutionary processes that generated a large proportion of the diversity of extant angiosperms. In light of these phylogenetic results, the current challenge for scientists in this area of botany is to identify the characters that are unique to the superasterid and superrosid clades and those that arose in parallel in both, and then to explore their evolutionary implications.