Equisetum or Horsetail
Equisetum is the scientific name for horsetail. In Latin equus means horse, and seta means brush. So the common name is an almost literal translation of the Latin name. In most places in the United States it is considered an invasive weed.1 The plant resembles a segmented asparagus, rather like bamboo.
Besides "horsetail", equisetum is also referred to as "marestail" and is thought of as a common scouring rush. This perennial is reed-like and gets to be about three feet tall, although there is a giant variety found in South America that can grow to 20 feet2.
The equisetum plant has a jointed and hollow stem. At each joint tiny leaves protrude. It is a Pteridophyte which means that it does not flower or produce seeds, rather it produces a "strobilus" at the top of the stem and spreads tiny spores.3
The horsetail plant can be found throughout the world. It is mostly found in damp and bogy places4. It will flourish in both tropical and temperate climates. It is fairly easy to cultivate. It can be easily spread by dividing. Although it does like damp conditions and is not tolerant of drought, marestail does not like to be completely submerged for long periods of time. It can be used in ornamental gardens, especially around pools.
Equisetum is harvested in some places, and used for scouring pans, and sometimes polishing furniture. The plant itself should not be eaten because it contains silica. However, it is used sparingly in some herbal remedies, usually in the form of E. arvense, which is considered the form most amenable to humans5. It is used in many supplements to help control bedwetting or enuresis6. It has also been used to treat osteoporosis, kidney stones, urinary tract infection, and wounds. It can also be found in many cosmetics and shampoos.7
People who rely on equisetum as a remedy should take care about overuse. It is known to deplete vitamin B 6 in the body. People with heart or kidney disorders should not take marestail as a supplement.8 It may also interact with medicines; so a doctor should be consulted, especially by those on medications.
- USDA Plant Profile
- Giant Equisetum
- Floridata - Equisetum
- E. arvense
- Medical Solutions to Bedwetting
- Uses of Equisetum
- Equisetum Precautions
- Image: USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. Vol. 1: 41.