Herb: Da Huang


Latin name: Rheum palmatum tanguticum


Synonyms: Rheum tanguticum


Family: Polygonaceae (Buckwheat Family)



Medicinal use of Da Huang:

Rhubarb 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. 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.

Description of the plant:



Plant:
Perennial


Height:
2 m
(6 1/2 foot)

Flovering:
June
to July

Habitat of the herb:

Valleys at elevations of 1600 - 3000 metres in Gansu, Qinghai and Xizang Provinces.

Edible parts of Da Huang:

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.

Propagation of the herb:

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.

Cultivation of Da Huang:

Valleys at elevations of 1600 - 3000 metres in Gansu, Qinghai and Xizang Provinces.

Known hazards of Rheum palmatum tanguticum:

Although no specific mention has been seen for this species, the leaves of some if not all members of this genus contain significant quantities of oxalic acid and should not be eaten in any quantity. Oxalic acid can lock up certain minerals in the body, especially calcium, leading to nutritional deficiency. The content of oxalic acid will be reduced if the plant is cooked. 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.

Plant information taken from the Plants For A Future.