Equisetum arvense, commonly known as the Field Horsetail or Common Horsetail, is a rather bushy perennial with a rhizomatous stem formation native to the northern hemisphere. These horsetails may have sterile or fertile stems. Sterile stems start to grow after the fertile stems have wilted. The sterile stems tend to be much taller and bushier, with the jointed segments being around one inch (2.5 cm) long with a diameter of about 1/20th of an inch (1 mm). These segments contain one set of whorled, slender, erect branches each. Some stems can have as many as 20 segments and be as tall as 2-24 inches (5–60 cm). The fertile stems tend to be half as tall as the sterile stems and also tend to be more succulent.
The plant contains several substances which can be used medicinally. It is rich in the minerals silicon (10%), potassium, and calcium, which gives it diuretic properties. It is prescribed to care for (cartilage, tendons, and bones) and also polyps, epistasis, and bleeding. The buds are eaten as a vegetable in Japan and Korea in spring time. All other Equisetum species are toxic. In polluted conditions, it may synthesise nicotine.
In herbalism it is used to treat kidney and bladder problems, gastro-enteritis, and prostate and urinary infections, and is particularly indicated for enuresis in children. Externally it is used for chilblains and wounds.