Paeonia suffruticosa Seeds | Peony Root Slices Mu Dan Pi Slices

Categories：(Root/ Flower /Fruit/ Leaf /Medicinal Animal)

Moutan root bark pieces, quilled and grey-brown outside — Moutan root bark (*Paeonia suffruticosa*): Paeoniaceae, native to central China.

LATIN NAME: Paeonia suffruticosa

COMMON NAME: Moutan Peony

Plant Profile

Moutan is the tree peony, a woody shrub one to two metres tall with deeply cut leaves and flowers up to twenty-five centimetres across in white, pink, red or purple. It is native to the mountains of Shaanxi, Henan and Anhui, and has been bred in China for fifteen centuries, first as a medicine and then as a garden plant.

Mu dan pi is not the flower or the root: it is the bark of the root, stripped in autumn from plants four to six years old, dried in the sun until it curls into quills, and sold in pieces that are grey-brown outside and pale yellow within. The bark is thin, brittle and easily broken, and the best pieces are the tight quills from the upper root.

Science & Biotechnology

The characteristic compound is paeonol, 2-hydroxy-4-methoxyacetophenone, present at one to three per cent in the bark and responsible for its sweet, slightly medicinal smell. Paeoniflorin and benzoylpaeoniflorin are also present, along with tannins and a little volatile oil.

Paeonol has been studied for anti-inflammatory action through NF-κB and COX-2 in cell and animal models, and it appears in some Chinese over-the-counter skin preparations. Human trials on the herb itself are scarce. The bark is one of the six ingredients of Liuwei Dihuang Wan and appears in dozens of other formulas.

Uses & Benefits

Decocted at six to twelve grams, mu dan pi is used in Chinese medicine for what is described as heat in the blood: nosebleeds, skin eruptions, low-grade fever in the afternoon. It is also a component of formulas for menstrual pain.

The main caution is pregnancy, where it is traditionally contraindicated because of its effect on uterine circulation. Gastrointestinal upset is the usual side effect. Because the bark is thin and expensive, pieces are sometimes padded with the bark of other peonies, which smell different and lack the paeonol crystals that frost the broken surface. It is also included in washes for inflamed skin, where the paeonol content is the reason for its inclusion.

Growing from Seed

Tree peonies are propagated by grafting in late August onto a piece of herbaceous peony root, which carries the scion through until it makes its own roots. Seed is possible but slow: it needs a warm period for the root to form and a cold one for the shoot, so germination takes eighteen months to two years.

Plants want deep, free-draining soil, full sun and a site where they are not moved. The stems die back partly each winter and are cut to a bud in spring. For bark, roots are lifted at four to six years in autumn, the bark stripped in lengths and dried; the plant is destroyed in the process, which is why good material is expensive.

Our Take

A garden plant of the first rank and a medicine of the second, whose bark is worth its price only when the pieces are heavy, yellow inside and sharp with paeonol.

(Root/ Flower /Fruit/ Leaf /Medicinal Animal)