Equisetum
Synonyms
Equisetaceae
Equisetums
Horsetail
Horsetails
The only living genus of the order Equisetales, class Equisetopsida (Sphenopsida), division Equisetophyta (Sphenophyta); distantly related to ferns. It grows in moist places. The hollow, jointed, ridged stems contain SILICATES.