Plants perennial, rhizomatous, with jointed, grooved stems. Leaves reduced, whorled, united into a sheath at the base. Sporophylls terminal, peltate, the blades adjoining each other and forming an ovoid strobilius; sporangia all alike, on the adaxial surface of the peltate heards; spores all alike, with elaters.
The Equisetaceae includes only one extant genus, Equisetum.
