Evolutionary Relationships of the Caryophyllidae Based on Comparative rbcL Sequences

In the long-standing controversy over the Centrospermae (i.e., Caryophyllales) and putatively related orders, comparative sequencing of the chloroplast gene, ribulose-1,5-bisphosphate carboxylase, large subunit (rbcL), shows that the Polygonales and Plumbaginales are not closely related to the Caryophyllales as has been hypothesized, nor are they related to members of the Dilleniidae. The sequence data supports the assignment of independent superorder status to the Caryophyllales and the Polygonales and Plumbaginales. These sequence data further suggest early and independent paths of evolution for the Polygonales and Plumbaginales, and the Caryophyllales.