Fagales

Fagales is an order of flowering plants in the rosids, a large clade within the angiosperms. In modern classifications it includes several woody families: Betulaceae (birches and alders), Fagaceae (oaks, beeches, and chestnuts), Juglandaceae (walnuts and pecans), Casuarinaceae (casuarinas), Myricaceae (bayberries), and Nothofagaceae (southern beech).

The order comprises mostly trees and shrubs. Leaves are typically simple and alternately arranged, often with serrated margins; many species are wind-pollinated. Fruits and seed structures vary by family, with nuts common in Fagaceae and other families producing nuts or nut-like fruits.

Fagales species are distributed worldwide, with a temperate to subtropical emphasis. Nothofagaceae is largely confined to the Southern Hemisphere, while the other families have broad distributions in both hemispheres. The group includes ecologically important temperate forests; oaks, beeches, walnuts, and chestnuts are notable for timber and edible nuts, and casuarinas are often used for timber and reforestation in certain regions.

Systematics: Modern classifications, including APG IV, recognize six families within Fagales. The order is placed among the rosids, within the clade Fabids, of the angiosperms. Earlier systems varied in circumscription, but the core composition has remained broadly consistent in recent classifications.