Horse tail

Horse tail, horsetail or horse's tail may refer to:


 * the tail of a horse
 * Equisetidae, a subclass of living and extinct plants known as horsetails
 * Equisetales, the single extant order of Equisetidae
 * Equisetaceae, the horsetail family, the only extant family of Equisetales
 * Equisetum, horsetail, the only living genus in Equisetaceae
 * Cauda equina ('horse's tail'), a bundle of spinal nerves and spinal nerve rootlets in humans
 * a type of waterfall