Mu Dan Pi, the bark of the tree peony
Mu Dan Pi is the root bark of the tree peony, the moutan peony: mu, the male, dan, the red, pi, the bark. Li Shizhen explains the “male”: the plant bears seeds, but mainly multiplies through shoots from its root. Under the Tang it was called the “woody peony”, as its flowers recall those of the herbaceous peony but it grows as a shrub. The bark comes from peonies cultivated for the pharmacopoeia, harvested in autumn after four to six years; its reference growing region is Anhui, first of all Mount Fenghuang, in Tongling. Good bark, thick and very fragrant, bears small shiny crystals on its inner face, the “silver stars”.
Cooling the Blood without congealing it
In traditional Chinese medicine, the bark is slightly cold, bitter and pungent in taste. The bitter and the cold clear, the pungent disperses: it enters the Blood level, cooling its Heat, and its pungency lets it vent that Heat rather than lock it in. Its three meridians, Heart, Liver and Kidney, all relate to the Blood or the Yin. A classical teaching sums up its balance: it cools the Blood without leaving stasis, and moves it without pushing it out of its pathways. Modern research is notably interested in paeonol, its aromatic compound.
The hidden heat of the Yin
When the Yin wears thin, a dull heat arises from within, which tradition says lies hidden in the Yin. Thanks to its pungency, Mu Dan Pi reaches the Yin to dislodge it: it “clears by bringing to the surface”. This is why it appears in so many formulas that nourish the Yin, such as Liu Wei Di Huang Wan, where it balances the warmth of the other herbs. Not to be confused with red peony root: another peony, another part, another use.
Key benefits
Heat cleared & Blood cooled
Bitter and cold, it clears Heat at the Blood level, and also knows how to vent it.
Blood in motion & smooth circulation
It supports Blood circulation without pushing the Blood out of its pathways, according to Chinese tradition.
Hidden heat soothed & Yin preserved
By dislodging the heat hidden in the Yin, it eases sensations of heat rising from within.
