Horsetail stands out among other plants due to its rare origin and little similarity to most of the inhabitants of flora kingdom. First, it is the descendant of the plants thriving in Paleozoic era (more than 400 million years ago), and second, it belongs to the Equisetum genus, the only existing in Equisetaceae family known for vascular plants propagated by spores. Consequently, horsetails are closely related to ferns, and similarly to the latter are considered to be non-flowering. The common name of the plant is based on its physical resemblance to the tail for the horse, while the Latin term for Equisetum means “horse bristle” (equus + seta). Depending on the region of spread, horsetails include both herbaceous an evergreen species, the latter being more characteristic of tropical and temperate zones. In general, the genus is found all over the world, save from Antarctica and Australia. The plants usually have a hollow stem, hollow shoots and leaves that do not perform photosynthesis. The highest horsetail species reach up to 8 m in height. The 1-4-cm-long yellowish-green spore cones are located on the top of the stem.
The dried stem of horsetail gets covered with silica crystals, giving the plant scratching properties. This quality made it useful for cleaning metal pottery and polishing woodcraft. In ancient times, particularly in Rome, horsetails were eaten fresh and cooked - prepared as asparagus. Although the aboveground horsetail has no nutritional value, it is still used in herbal medicine, both fresh and dried. Rhizomes of the plant are used for the starch cells containing in them in high amounts.
Most common herbal preparations from horsetail are liquid and dried extracts, decoctions, infusions and compresses for topical applications. To preserve medical value of these, they are recommended to be stored in properly sealed containers with no access of direct light.
The major chemical value of horsetails is in the silicic acid and silica content. These components extracted from the stem of the plant enhance the formation of collagen and thus help mending broken bones and providing protein to the skin, cartilage, connective tissues and ligaments. Other components in the herb include a variety of flavonoids, aluminum, potassium, and manganese. Horsetails are considered to be diuretic (flavonoids + saponins), wound healing, antibacterial, astringent, antioxidant and anti-rheumatic.
The history of horsetail use roots back to ancient Rome and Greece. Herbalists of those times knew wound healing properties of the plant and used it to heal ulcers, stop bleeding, and even help kidney conditions.
In modern herbal medicine it is applied for treating rheumatism and calcium insufficiency symptoms.
Horsetail tea helps strengthening the nails, hair, bones, and connective tissues. Also, plant's herbal blends enhance the production of white blood cells and help the body to better absorb calcium.
Diuretic and astringent properties of the plant make it effective in treating genito-urinary tract conditions. It helps in bed-wetting, cystitis, menopausal oedema, kidney disorders, pelvic disease (with no inflammation), and the inflammation of the prostate.
Due to the ability of the silicic acid to heal the scar tissue, horsetail is applied for the tuberculosis patients – it restores pulmonary tissue damaged by the disease.
Blood clotting effects of the horsetail juice are used for mouth, nose, bowel and vaginal bleeding, for the wounds that are slow in healing, stomach ulcers and conjunctivitis. Usually topical applications are used for these cases, or as in case of internal bleeding – tea should be made. Horsetail tea is also applied topically: compresses are good for skin problems, wounds, burns, scratches, and the gargle is helpful for inflammation of the mouth of gum.
Horsetail is also associated with such conditions as diabetes, dyspepsia, fever, gonorrhea, liver disorders, thyroid disorders and hepatitis.
Most of the health benefits of the horsteail have been subjected to few human studies, but medical researches prove the effectiveness of its major components.