Coptis japonica

Family: Ranunculaceae

What it is like

Coptis japonica is an evergreen Perennial growing to 0.2 m (0ft 8in) by 0.5 m (1ft 8in). See above for USDA hardiness. It is hardy to UK zone 7. It is in leaf all year, in flower in May. The species is hermaphrodite (has both male and female organs). Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 0.2

Where it is found

Woods in mountains all over Japan.

E. Asia - Japan.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 0

Medicine

Rating: 2

The root is a pungent, very bitter, cooling herb that controls bacterial and viral infections, relaxes spasms, lowers fevers and stimulates the circulation. It is locally analgesic and anaesthetic and is also anti-inflammatory and stomachic. It is used in the treatment of intestinal catarrh, dysentery, enteritis, high fevers, inflamed mouth and tongue, conjunctivitis etc. The root is harvested in the autumn and can be used fresh or dried.

Antibacterial: Kills bacteria.

Antiinflammatory: Reduces inflammation of joints, injuries etc.

Dysentery: Used in treating dysentery - an infection of the intestines that causes diarrhoea containing blood or mucus.

Stomachic: Aids and improves the action of the stomach.

Other

Rating: 3

Can be grown as a ground cover plant in the peat garden.

Ground cover: Ground Cover

How it is grown

Requires a light moist humus-rich slightly acidic soil with a northerly aspect or light shade.

Propagating it: Seed - best sown in a greenhouse as soon as it is ripe in an ericaceous compost. Seal the pot in a polythene bag until germination takes place, which is usually within 1 - 6 months at 10°c. Stored seed should be sown as early in the year as possible. Four weeks cold stratification may be beneficial. Prick out the seedlings into individual pots when they are large enough to handle and grow on in a shady part of the greenhouse for at least their first winter. Plant them out in mid-autumn or in spring. Division in spring.

Best place to grow: Woodland Garden Dappled Shade; Shady Edge; Ground Cover;

Habit: Perennial

Hardiness: 6-9

Growth:

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Although no specific mention of toxicity has been found for this species, it belongs to a family that contains many species that are mildly toxic and so it is wise to treat this plant with some caution.

Its other names

Local names

Synonyms

C. anemonaefolia. Sieb.&Zucc. C. orientalis. Thalictrum japonicum.