Kingdom [Plantae] Haeckel (1866) - plants Division Pteridophyta Schimp. (1879) see Subphylum Pteridophytina (Eichler) Cavalier-Sm. (1998) Class Equisetopsida C.Agardh (1825) - horsetails see Subclass Equisetidae Warm. (1883) Order Equisetales DC. ex Bercht. & J.Presl (1829) Family †Calamostachyaceae S.V.Meyen (1978), nom. cons. prop.