Specification :

A small perennial, scattered in the moss of strata of coniferous forests at altitudes of 1,000-1,800 m. The rhizome is creeping and developing horizontally. It is composed of almost erect shoots with dense spiral leaves, and a solitary spike-shaped sporangium at the top. The whole plant including the spores is used medically for the treatment of rheumatism and arthritis, to stimulate the circulation of the blood and to cause the muscles and joints to relax.