Drynaria fortunei: also known as Zingiber officinale, is the rhizome of Quercus variabilis, a Polypodiaceae plant.

Tropism of nature and taste: warm in nature and bitter in taste. Entering liver and kidney meridians

Functions: it is mainly used for tonifying kidney and strengthening bones, and relieving pain. It can be used for treating lumbago due to kidney deficiency, chronic diarrhea due to kidney deficiency, tinnitus and deafness, tooth looseness, stumbling,

Tendon fracture injury; External treatment of alopecia areata and vitiligo.

Usage and dosage: decoct 4.5-9g for external use.

Taboo: those with deficiency of fire, blood, yin and blood stasis should take it with caution.