Marestail

Marestail (also mare's tail and mare's-tail) may refer to:

Plants

 * Conyza canadensis, an annual weed also known as horseweed and Canadian fleabane
 * Equisetum, a fern ally also known as horsetail and pipeweed
 * Hippuris, a genus of aquatic flowering plants, including:
 * Hippuris vulgaris, the common mare's-tail

Other

 * Mare's tail, a type of cirrus cloud formation