Temperate and warm regions, worldwide except Australia.
In addition to the characters given in the key to families, wood anatomy can be used to distinguish Ephedra from the other gymnosperms in the flora. Only Ephedra has small cones, ring porous wood, wide multiseriate rays, and vessels in older stems.
Since antiquity, several species of Ephedra have been used medicinally worldwide. Such uses include cough medicines, an antipyretic, an antisyphilitic, a stimulant for poor circulation, and an antihistamine. These uses are based on the presence of tannins and alkaloids, particularly ephedrines.
Genus 1, species ca. 60 (12 species in the flora).