Fagales

The Fagales are an order of flowering plants, including some of the best-known trees. The order name is derived from genus "Fagus", beeches. They belong among the rosid group of dicotyledons. The families and genera currently included are as follows:
The older Cronquist system only included four families (Betulaceae, Corylaceae, Fagaceae, Ticodendraceae; Corylaceae now being included within Betulaceae); this arrangement is followed by, for example, the World Checklist of selected plant families. The other families were split into three different orders, placed among the Hamamelidae. The Casuarinales comprised the single family Casuarinaceae, the Juglandales comprised the Juglandaceae and Rhoipteleaceae, and the Myricales comprised the remaining forms (plus "Balanops"). The change is due to studies suggesting the Myricales, so defined, are paraphyletic to the other two groups.
Systematics.
Modern molecular phylogenetics suggest the following relationships: