Equisetum arvense, the field horsetail or common horsetail is a herbaceous perennial plant, native throughout the arctic and temperate regions of the northern hemisphere.
It has separate sterile non-reproductive and fertile spore-bearing stems, growing from a perennial underground rhizomatous stem system.
Horsetail is a member of the Equisetaceae family; the sole survivor of a line of plants going back three hundred million years. The name “horsetail”, often used for the entire group, arose because the branched species somewhat resemble a horse’s tail.
It is commonly confused with mare’s tail, Hippuris vulgaris.