In the treatment by King and Robinson (Monogr. Syst. Bot. 22: 1-581. 1987) Eupatorium japonicum Thunb., was treated as a synonym of Eupatorim chinense L. Whilst this treatment has been accepted by some, others (such as 'The Flora of China[]') have maintained the two taxa as distinct - a treatment we are following here.

Common Name: Pei Lan

General Information

Eupatorium japonicum is an erect, herbaceous perennial plant producing a clump of usually unbranched stems 50 - 200cm tall[].
The plant is harvested from the wild for local use as a food and medicine and is cultivated for medicinal use in Japan and Vietnam[].

Known Hazards

None known

Botanical References

, ,

Range

E. Asia - China, Japan, Korea, Vietnam.

Habitat

Grasslands on slopes, lax forests, thickets, wet places, riverbanks; at elevations from 100 - 3,000 metres[]. Moist grassland along river banks[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	2.00 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Succeeds in ordinary well-drained but moisture retentive garden soil in sun or part shade[].
A very polymorphic species[], it is closely related to E. cannabinum[].
This species is a member of natural moist grassland flora on river banks in the Kanto District of Japan. Due to urbanization of this area, the habitat is now restricted to a very small area, and the species is endangered[].
Plants seem to be immune to the predations of rabbits[].

Edible Uses

Young leaves - cooked. Boiled and well seasoned[].

Root - cooked. It is sometimes eaten for food and is considered beneficial to the circulation[].

Medicinal

The leaves and stems are anodyne, antibacterial, antiviral, carminative, diaphoretic, diuretic, nervine and vermifuge[, ]. They are taken internally in the treatment of indigestion, nausea, vomiting, diarrhoea, feverish colds etc[, , ].
In excess the plant causes irritation to the stomach[].
Use with caution[]. The plant contains the essential oil thymol. In large doses this can cause various health problems such as headaches, tinnitus, vertigo, inhibition of respiration and the circulation[].
The leaves and stems are harvested in the summer before the flower buds open, and are dried for later use[].

The seed is prescribed in China for the '36 diseases of women'[].

The root is considered to be beneficial to the circulation and a restorative to women after parturition[]. It is harvested in the autumn and dried for later use[].

The herbage, soaked in oil, is applied to the hair as a treatment for dandruff[].

Other Uses

None known

Propagation

Seed - sow spring in a cold frame and only just cover the seed. Prick out the seedlings into individual pots when they are large enough to handle and plant them out into their permanent positions in the summer.
Division in spring or autumn[]. Very easy, the clumps can be replanted direct into their permanent positions.