Horsetail

Horsetail contains high concentrations of silicic acid and other silicates. Horsetail also contains potassium and manganese, along with variety of flavonoids. These flavonoids, as well as other substances found in horse tail, most importantly are the silicates found in horsetail which are believed responsible for the herb's ability to strengthen connective tissue and give it anti-arthritic actions. A few herbal specialists believe that the organic silicon concentrations found in horsetail may also promote bone and cartilage formation and are useful for treating brittle nails and related conditions.