Common Name: Chinese Rhubarb

General Information

Rheum officinale is a herbaceous perennial plant growing from a stout, woody, rhizomatous rootstock; it produces a basal clump of leaves up to 30 - 50cm in diameter on petioles that are up to 45cm long; the plant flowers in the summer, producing stout flowering stems around 150 - 200cm tall[].
The plant is harvested from the wild for local use as a food, medicine and source of materials. It is one of several species of Rheum used in Japan for medicinal purposes and is included in the Japanese Pharmacopoeia[], It is cultivated for medicinal use in China, and is also grown as an ornamental[, ].

Known Hazards

The plant, but especially the leaf blades, contains several toxic compounds, particularly anthraquinone glycosides, but also soluble oxalates and calcium oxylate crystals[, , ]. At lower doses these can cause abdominal cramps, burning of the mouth and throat, headache, weakness, nausea and vomiting. In larger, quantities it can lead to coma and death, though generally very large quantities need to be eaten for the plant to be fatal.
The leaf stems (petioles) have much lower quantities of toxins and, in several Rheum species are a commonly eaten food. The main caution here are the levels of oxalates. These can lock up certain minerals (especially calcium) in the body, leading to nutritional deficiency. Cooking the plant will reduce the concentration 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[].

Botanical References

,

Range

E. Asia - central and eastern China.

Habitat

Hills and forest understories; at elevations from 1,200 - 4,000 metres in western China[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	2.00 m
Pollinators	Wind
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Rheum officinale is a fairly cold-hardy plant, tolerating winter temperatures down to about -20°c[].
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 grow well along the woodland edge or amongst large shrubs[]. They can be grown in quite coarse grass, which can be cut annually in the autumn[].
Closely related to Rheum australe[].
Hybridizes freely with other members of this genus[].
Plants at the Cambridge Botanical Gardens in September 1993 were growing well in the shade of a woodland garden, though they were not succeeding when planted closely to the trees[].
Plants in this genus seem to be immune to the predations of rabbits[].

Edible Uses

Leaf stem - cooked or raw[, ]. Rather medicinal[].
One report says that the plant contains 1.3% rutin[]. It does not specify which part of the plant, though it is likely to be the leaves[].

Medicinal

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[]. The roots contain tannins and, when taken in small doses acts as an astringent tonic to the digestive system, relieving diarrhoea. At larger doses, however, the anthraquinones in the root exert their influence as a mild laxative and are a gentle treatment for constipation[, ]. The root is taken internally in the treatment of chronic constipation, diarrhoea, indigestion, 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[].

Agroforestry Uses:

Plants can be grown for ground cover when spaced about 1.8 metres apart each way[].

Other Uses

None known

Propagation

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.