Common Name:

General Information

Rheum webbianum is a herbaceous perennial plant growing from a stout, woody, rhizomatous rootstock; it produces a basal clump of leaves up to 20 - 25cm long and 25 - 30cm wide on stout petioles that are up to 15cm long; the plant flowers in the summer, producing unbranched flowering stems up to 55cm tall[].
The plant is harvested from the wild for local use as a food. It has very similar medicinal properties to the Himalayan Rhubarb (Rheum australe) and is harvested in quantity and mixed with that species in trade[].

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 - Himalayas of Pakistan, northwest India, Nepal and Tibet

Habitat

Slopes; at elevations around 3,500 - 3,600 metres[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	0.50 m
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

Rheum webbianum is a moderately cold-hardy plant, tolerating winter temperatures that can fall to about -20°c[].
Rheum species generally prefer a deep, fertile, moderately heavy, humus rich, moisture retentive, well-drained soil in sun or semi-shade[]. They grow well along the woodland edge or amongst large shrubs[]. They succeed in heavy clay soils.
Plants in this genus seem to be immune to the predations of rabbits[].
Hybridizes freely with other members of this genus[].

Edible Uses

Leaf stems - cooked. An acid flavour[]. The report actually says it is the leaves and tendrils that are eaten, but this is an error[].

Medicinal

This species has very similar properties to the Himalayan Rhubarb (Rheum australe) and is commonly mixed with that species in trade[]. The main properties of Rheum australe are:-
The root is anticholesterolemic, antiseptic, antispasmodic, antitumor, aperient, astringent, cholagogue, demulcent, diuretic, laxative, purgative, stomachic and tonic[, , , , , , , ]. The roots contain tannins and, 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, liver and gall bladder complaints, blood disorders, haemorrhoids, menstrual problems, sore throats and skin eruptions due to an accumulation of toxins[, ]. When taken internally, the root imparts a deep tinge to the urine[].
Applied externally, the root is used in the treatment of burns[]. A paste of the rootstock is used in treating scabies and other skin diseases[]. Combined with other herbs, the paste is applied to fix fractured bones, swellings, sprains etc[].

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.