Goldthread, Threeleaf goldthread
Coptis trifolia
Family: Ranunculaceae
What it is like
A good forest garden plant. Coptis trifolia subsp. groenlandica (Oeder) Hultén is a smaller subspecies of Coptis trifolia growing to 2-4" (5-10cm).
Coptis trifolia 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 2. 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). It prefers moist soil.
Height (m): 0.2
Where it is found
Wet to mesic, coniferous and mixed forests, bogs, willow scrub, and tundra, often associated with mosses from sea level to 1500 metres.
North, eastern and western N. America through northern Asia to Japan.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 2
The whole plant is said to be eaten, or it can be mixed with sassafras-root bark and Irish moss and brewed into a kind of herbal root beer. This plant contributes a bitter flavour and a yellow colour to the beverage. Some caution is advised, see the notes above on toxicity.
Condiment: the various plants that are used as flavourings, either as herbs, spices or condiments.
Medicine
Rating: 2
Goldenthread is a very bitter tasting herb that was formerly highly valued and widely used in North America by the native Indians and white settlers alike, though it is little used in modern herbalism. It was employed mainly to treat any soreness in the mouth. The dried roots, stems and leaves are antiphlogistic, highly astringent, sedative, stomachic, tonic. The plant is valued as a local application in the treatment of thrush in children. It is also used in the treatment of ulcerated mouths and as a gargle for sore throats or mouths. It is said to be useful in the treatment of dyspepsia and helpful in combating the drink habit. The plant contains the alkaloid 'berberine', which is a mild sedative, anti-inflammatory and antibacterial. The root is collected in the autumn and dried for later use.
Antibacterial: Kills bacteria.
Antiinflammatory: Reduces inflammation of joints, injuries etc.
Antiphlogistic: Reduces inflammation.
Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.
Sedative: Gently calms, reducing nervousness, distress and irritation.
Skin: Plants used in miscellaneous treatments for the skin.
Stomachic: Aids and improves the action of the stomach.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Other
Rating: 2
A yellow dye is obtained from the leaves and stems. Can be grown as a ground cover plant in the peat garden.
Dye: Plants that provide dyes.
Food Forest: Plants for Edible Forest Gardens and Food Forests.
Ground cover: Ground Cover
How it is grown
Requires a light moist humus-rich slightly acidic soil with a northerly aspect or light shade. A very ornamental plant. The sub-species C. trifolia groenlandica (Syn C. groenlandica) is the form used medicinally in N. America. The plant is heat tolerant in zones 7 through 1. (Plant Hardiness Zones show how well plants withstand cold winter temperatures. Plant Heat Zones show when plants would start suffering from the heat. The Plant Heat Zone map is based on the number of "heat days" experienced in a given area where the temperature climbs to over 86 degrees F (30°C). At this temperature, many plants begin to suffer physiological damage. Heat Zones range from 1 (no heat days) to 12 (210 or more heat days). For example Heat Zone. 11-1 indicates that the plant is heat tolerant in zones 11 through 1.) For polyculture design as well as the above-ground architecture (form - tree, shrub etc. and size shown above) information on the habit and root pattern is also useful and given here if available. An evergreen. The plant growth habit is a runner spreading indefinitely by rhizomes or stolons. The root pattern is rhizomatous with underground stems sending roots and shoots along their length.
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: 2-7
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: Semi-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. groenlandica. (Oeder.)Fern.