Turkey Rhubarb, Chinese Rhubarb - Da Huang, Chinese rhubarb
Rheum palmatum

Family: Polygonaceae

What it is like

Rheum palmatum is a PERENNIAL growing to 3 m (9ft) by 2 m (6ft). See above for USDA hardiness. It is hardy to UK zone 7. It is in flower from June to July, and the seeds ripen from July to September. The species is hermaphrodite (has both male and female organs) and is pollinated by Wind. Suitable for: medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in heavy clay soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 3

Where it is found

Scrub and rocky places and by streams, 2500 - 4000 metres. Slopes and valleys at elevations of 1500 - 4400 metres in western and northern China.

E. Asia - N.W. China in Yunnan, W. Sichuan, E. Xizang and Gansu.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 3

Leaf stem - raw or cooked. The stem is superior in flavour to the common rhubarb and quite tender. An acid flavour, it is sometimes used as a cooked fruit substitute.

Stem: this often intergrades into leaves.

Medicine

Rating: 5

Chinese rhubarb, called Da Huang in China, has a long and proven history of herbal usage, its main effect being a positive and balancing effect upon the whole digestive system. It is one of the most widely used herbs in Chinese medicine. It has a safe and gentle action, safe even for children to use. The plant is also part of a North American formula called essiac which is a popular treatment for cancer. Its effectiveness has never been reliably proven or disproven since controlled studies have not been carried out. The other herbs included in the formula are Arctium lappa, Ulmus rubra and Rumex acetosella. The root is anticholesterolemic, antiseptic, antispasmodic, antitumor, aperient, astringent, cholagogue, demulcent, diuretic, laxative, purgative, stomachic and tonic. The roots contain anthraquinones, which have a purgative effect, and also tannins and bitters, which have an opposite astringent effect. When taken in small doses, it acts as an astringent tonic to the digestive system, whilst larger doses act as a mild laxative. The root is taken internally in the treatment of chronic constipation, diarrhoea, liver and gall bladder complaints, haemorrhoids, menstrual problems and skin eruptions due to an accumulation of toxins. This remedy is not prescribed for pregnant or lactating women, nor for patients with intestinal obstruction. Externally, the root is used in the treatment of burns. The roots are harvested in October from plants that are at least six years old, they are then dried for later use. A homeopathic remedy is prepared from the dried root. This is used especially in the treatment of diarrhoea in teething children. The German Commission E Monographs, a therapeutic guide to herbal medicine, approve Rheum palmatum for constipation.

Anticholesterolemic: Prevents the build up of cholesterol.

Antiseptic: Preventing sepsis, decay or putrefaction, it destroys or arrests the growth of micro-organisms.

Antispasmodic: Relaxes muscular spasms and cramps, calming nervous irritation.

Antitumor: Preventing, or effective against, tumors, it is used in the treatment of cancer. Probably synonymous with Cytotoxic.

Aperient: A mild laxative.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Cholagogue: Increases the flow of bile and its discharge from the body.

Demulcent: Soothes, lubricates and softens irritated tissues, especially the mucous membranes.

Diuretic: Acts on the kidneys, promoting the flow of urine.

Homeopathy: A plant used in homeopathic treatments.

Laxative: Stimulates bowel movements in a fairly gentle manner.

Purgative: A drastic laxative causing a cleansing or watery evacuation of the bowels, usually with a griping pain.

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

An insect spray is made from the leaves. This spray is also said to help prevent clubroot of brassicas. The cultivar 'Atrosanguineum' can be used as a ground cover plant in a sunny position. Other forms can also be used, they are best planted about 1.8 metres apart each way.

Fungicide: Arrests the growth of, or kills, fungi.

Insecticide: Kills insects.

Food Forest: Plants for Edible Forest Gardens and Food Forests.

Ground cover: Ground Cover

How it is grown

Prefers a deep, fertile, moderately heavy, humus rich, moisture retentive, well-drained soil in sun or semi-shade. Grows well in heavy clay soils. Plants can be grown in quite coarse grass, which can be cut annually in the autumn. Hardy to at least -15°c. A very ornamental plant, there is at least one named variety. Hybridizes freely with other members of this genus. The sub-species R. palmatum tanguticum is cultivated as a medicinal plant in China, it was at one time a popular purgative in Europe. Plants in this genus seem to be immune to the predations of rabbits. Turkish rhubarb is a good companion plant for columbine (Aquilegia spp). The plant is heat tolerant in zones 9 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. The plant growth habit is a clumper with limited spread.

Propagating it: Seed - best sown in autumn in a shaded cold frame. The seed can also be sown in spring in a cold frame. When large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse or cold frame for their first winter, planting them out in the spring. Division in early spring or autumn. Divide up the rootstock with a sharp spade or knife, making sure that there is at least one growth bud on each division. Larger divisions can be planted out direct into their permanent positions. We have found that it is better to pot up the smaller divisions and grow them on in light shade in a cold frame until they are well established before planting them out in late spring or early summer.

Best place to grow: Ground Cover; Cultivated Beds;

Habit: Perennial

Hardiness: 6-9

Growth:

Soil: Medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

The leaves are poisonous. This report probably refers to high levels of oxalic acid found in the leaves. Perfectly safe in moderate quantities, oxalic acid can lock up certain minerals (especially calcium) in the body, leading to nutritional deficiency. Cooking the plant will reduce its content of oxalic acid. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition. Laxative action side-effect with long term use may lead to electrolyte imbalances. Increase in aldosterone secretion, passage of albumin and blood in urine and intestinal movement loss .

Its other names

Local names

Synonyms

Rheum potaninii, Rheum qinlingense, Rhabarbarum palmatum Moench: Unresolved