Equisetum Arvense: One of the Plants Richest in Silica
Horsetail, Equisetum arvense, is a perennial plant belonging to the Equisetaceae family. It is a survivor from the Carboniferous period, a geological era dating back hundreds of millions of years. Horsetail is, in fact, considered a ‘living fossil’. Equisetum means ‘horse’s mane’, while arvense means ‘fields’, hence its other name, ‘horsetail’.
The plant can grow up to 1 metre in height. Horsetail produces two types of stem: a fertile stem, which is smooth and brown in colour and bears the spores in spring. Once the spores have been dispersed, this stem withers. The second type is the sterile stem. This stem is green and resembles a horse’s tail, hence the plant’s common name. It is this stem that contains a significant amount of silicic acid, a soluble form of silica.
Field horsetail grows mainly in damp soils, including ditches, meadows, and cultivated fields. This species is found on most continents except Australia and Antarctica. Horsetail has been associated with human activities since at least ancient times: it was used by the Romans to polish metals such as copper and bronze. It is also used to make baskets, brushes, and brooms. Finally, its therapeutic properties have long been recognised.
Marsh Horsetail or Field Horsetail?
Only field horsetail is used in herbal medicine. It is therefore important to identify it correctly to avoid any confusion with marsh horsetail (Equisetum palustre), which is toxic to both livestock and humans.








