Polygonales has been an Order in old taxonomies, associated with Caryophyllales. It included the Polygonaceae and Plumbaginaceae, which in Stebbins classification was placed in its own Order. In the Apg2 classification Polygonales included also Droseraceae and related carnivorous Families. In the Apg3 classification Polygonales is included in Caryophyllales.
In the Plant theory Polygonales is split off from Caryophyllales. Droserales is split off from Polygonales, both being monophyletic. Simmondsiaceae is placed in Polygonales, following Kadereit.
Eriogonaceae is split off from Polygonacaeae, both being monophyletic.